Ink set, ink cartridge, ink jet printer and recording method

ABSTRACT

The ink set of the present invention provides a high ejection stability, gives an image having an excellent hue, light-resistance and waterproofness and improves the image preservability under severe conditions in ink jet recording, in which the ink set comprising a plurality of inks different in hues, wherein the plurality of inks includes a yellow ink containing a coloring agent that is a dye having: a λmax of from 390 nm to 470 nm; an I(λmax+70 nm)/I(λmax) ratio of not greater than 0.4, in which I(λmax) is the absorbance at λmax and I(λmax+70 nm) is the absorbance at (λmax+70 nm); and a forced fading rate constant of not greater than 5.0×10 −2  [hour −1 ], an ink cartridge having the ink set received therein, an ink jet printer comprising the ink cartridge mounted therein and an image recording method.

CROSS REFERENCE TO RELATED APPLICATION

This application is a Divisional Application of U.S. application Ser.No. 10/645,795 filed Aug. 22, 2003, which application is incorporatedherein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to an ink set for ink jet recording whichgives an image having a high quality and exhibits an excellentpreservability and ejection stability, a cartridge comprising same andan image recording method using same.

BACKGROUND OF THE INVENTION

In recent years, with the spread of computers, ink jet printers havebeen widely used to print on paper, film, cloth, etc. at offices as wellas at home.

Examples of ink jet recording method include a method which allows apiezoelectric element to give pressure that causes a droplet to beejected, a method which comprises heating the ink to generate bubbles,causing a droplet to be ejected, a method involving the use ofultrasonic wave, and a method which uses electrostatic force to suck anddischarge a droplet. As inks for these ink jet recording methods thereare used aqueous inks, oil-based inks and solid (melt type) inks. Amongthese inks, aqueous inks are mainly used from the standpoint ofproducibility, handleability, odor, safety, etc.

The dyes to be incorporated in these inks for ink jet recording arerequired to exhibit a high solubility in solvents, allow a high densityrecording and have a good hue and an excellent fastness to light, heat,air, water and chemical, a good fixability to image-receiving materials,difficulty in running, an excellent preservability, no toxicity and ahigh purity and be available at a low cost. However, it is extremelydifficult to seek coloring agents meeting these requirements to a highextent. In particular, dyes having a good magenta hue and an excellentlight fastness have been keenly desired.

Various dyes and pigments have been already proposed for ink jetrecording and have been actually used. However, no coloring agentsmeeting all these requirements have been found yet. Known dyes andpigments provided with color index (C.I.) can difficultly satisfy boththe hue and fastness requirements for inks for ink jet recording. Asdyes capable of enhancing fastness there have been proposed azo dyesderived from aromatic amines and 5-membered heterocyclic amines inJP-A-55-161856. However, these dyes are disadvantageous in that theyhave an undesirable hue in yellow and cyan ranges, causing deteriorationof color reproducibility. JP-A-61-36362 and JP-A-2-212566 disclose inksfor ink jet recording intended to meet both the requirements for hue andlight-fastness. However, the dye stuffs used in the above cited patentsexhibit an insufficient water solubility when used as water-solubleinks. These dyestuffs are also disadvantageous in that when used aswater-soluble inks for ink jet recording, they also cause problems ofwet heat fastness. As means for solution to these problems there havebeen proposed compounds and ink compositions in JP-T-11-504958. Further,inks for ink jet recording which comprise pyrazoloaniline azoincorporated therein to improve hue or light-fastness are disclosed inJapanese Patent Application No. 2000-80733. However, these inks for inkjet recording have been found disadvantageous in that they can causeimage deterioration under severe conditions such as prolonged storage athigh temperatures or in the presence of gas such as nitrogen oxide andozone. In order to eliminate these difficulties, the kind of dyes to beused have been studied. For secondary colors such as blue or gray,however, the effect of enhancing fastness cannot be sufficientlyobserved due to ill-balanced hues merely by changing one dye. Further,the mixing of two dyes causes interaction that can further deterioratefastness. It has thus been desired to provide an ink set, cartridge andprinter capable of remarkably enhancing fastness to give a high fastnessimage.

SUMMARY OF THE INVENITON

It is therefore an aim of the invention to provide an ink excellent inhandleability, odor, safety, etc. which exhibits a high ejectionstability and gives an image having an excellent hue, light-resistanceand waterproofness free of defectives of image quality such as runningof fine line and having an improved preservability under severeconditions. It is another aim of the invention to provide an ink set,cartridge and image recording method which exhibit a high ejectionstability over an extended period of time even after aged under severeconditions.

The inventors made studies. As a result, it was found that the use of aspecific yellow ink as an ink for ink jet recording makes it possible toobtain a high fastness printed matter without any image deteriorationeven under severe conditions such as prolonged storage at hightemperatures or in the presence of gas or the like. The imagedeterioration under severe conditions and/or in the presence of gasoccur remarkably with an image-receiving paper comprising a whiteinorganic pigment incorporated in an image-receiving layer. It ispresumed that this image deterioration is attributed to the reactionwith the white inorganic pigment itself or the effect of the gascomponent adsorbed to the white inorganic pigment besides the heatdeterioration reaction.

In other words, the invention concerns an ink cartridge having aspecific yellow ink received therein integrally or independently atleast partly, wherein a magenta ink and a cyan ink are used incombination. The invention further concerns an ink jet printer and animage recording method using the ink set or ink cartridge.

In other words, the invention concerns the following ink set, inkcartridge, ink jet printer and image recording method.

1. An ink set comprising a plurality of inks different in hues, whereinthe plurality of inks includes a yellow ink containing a coloring agentthat is a dye having:

a λmax of from 390 nm to 470 nm;

an I(λmax+70 nm)/1 (λmax) ratio of not greater than 0.4, in whichI(λmax) is the absorbance at λmax and I(λmax+70 nm) is the absorbance at(λmax+70 nm); and

a forced fading rate constant of not greater than 5.0×10⁻² (hour⁻¹), inwhich the forced fading rate constant is decided by dissolving and/ordispersing the dye in an aqueous medium to form an ink composition forink jet recording, printing the ink composition on a reflection typemedium, thereafter measuring a reflection density through a Status Afilter, specifying one point having a reflection density (DB) in anyellow region of 0.90 to 1.10 as an initial density of the ink, forcedlyfading the printed matter by use of an ozone fading tester that canregularly generate 5 ppm of ozone, and determining the time taken untilthe reflection density reaches 80% of the initial density.

2. The ink set as described in the item 1, wherein the dye has the λmaxof from 390 nm to 470 nm and the I(λmax+70 nm)/I(λmax) ratio of notgreater than 0.2.

3. The ink set as described in the item 1, wherein the dye has anoxidation potential of higher than 1.0 V (vs SCE).

4. An ink set comprising a plurality of inks different in hues, whereinthe plurality of inks includes a yellow ink containing a coloring agentthat is a dye represented by the following general formula (1), the dyehaving a λmax of from 390 nm to 470 nm:A−N=N−B  (1)wherein A and B each independently represent a heterocyclic group whichmay be substituted.

5. The ink set described in the item 1 or 4, which further comprises atleast a coloring agent represented by the following general formula(M-I) as the magenta ink:

wherein A¹ represents a residue of a 5-membered heterocyclic diazocomponent A¹-NH₂; B¹ and B² each represent a nitrogen atom, —CR¹═ or—CR²═, and when one of B¹ and B² represents a nitrogen atom, the otherrepresents —CR¹═ or —CR²═; R⁵ and R⁶ each independently represents ahydrogen atom, an aliphatic group, an aromatic group, a heterocyclicgroup, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group,a carbamoyl group, an alkyl- or arylsulfonyl group or a sulfamoyl group,which may further have a substituent group; G¹, R¹ and R² eachindependently represents a hydrogen atom, a halogen atom, an aliphaticgroup, an aromatic group, a heterocyclic group, a cyano group, acarboxyl group, a carbamoyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a heterocyclic oxycarbonyl group, an acyl group,a hydroxyl group, an alkoxyl group, an aryloxy group, a heterocyclic oxygroup, a silyloxy group, an acyloxy group, a carbamoyloxy group, analkoxy-carbonyloxy group, an aryloxycarbonyloxy group, an amino group(containing a heterocyclic amino group and an anilino group), anacylamino group, a ureido group, a sulfamoylamino group, analkoxycarbonylamino group, an aryloxycarbonylamino group, an alkyl- orarylsulfonylamino group, a heterocyclic sulfonylamino group, a nitrogroup, an alkyl- or arylthio group, an alkyl- or arylsulfonyl group, aheterocyclic sulfonyl group, an alkyl- or arylsulfinyl group, aheterocyclic sulfinyl group, a sulfamoyl group, a sulfo group or aheterocyclic thio group, which may be further substituted; and R¹ andR⁵, or R⁵ and R⁶ may combine with each other to form a 5- or 6-memberedring.

6. The ink set described in the item 1 or 4, which further comprises acoloring agent represented by the following general formula (C-I) as thecyan ink:

wherein X¹, X², X³ and X⁴ each independently represent —SO-Z¹, —SO₂Z¹,—SO₂NR²¹R²², CONR²¹R²² or —CO₂R²¹ n which Z¹ represents a substituted orunsubstituted alkyl, cycloalkyl, alkenyl, aralkyl, aryl or heterocyclicgroup; and R²¹ and R²² each independently represent a hydrogen atom or asubstituted or unsubstituted alkyl, cycloalkyl, alkenyl, aralkyl, arylor heterocyclic group; Y¹, Y², Y³ and Y⁴ each independently represent amonovalent substituent; a1 to a4 and b1 to b4 each independentlyrepresent an integer of from 0 to 4 indicating the number ofsubstituents X¹ to X⁴ and Y¹ to Y⁴, with the proviso that a1 to a4 arenot 0 at the same time and when a1 to a4 and b1 to b4 each represent aninteger of not smaller than 21 the plurality of X¹'s to X⁴'s and Y¹'s toY⁴'s may be the same or different; and M represents a hydrogen atom or ametal atom, or oxide, hydroxide or halide thereof.

7. The ink set as described in the item 5, wherein the magenta inkincludes a set of two or more inks different in ink concentration, andthe ink concentration of one magenta ink is 0.05 to 0.5 time that of theother magenta ink.

8. The ink set as described in the item 6, wherein the cyan ink includesa set of two or more inks different in ink concentration, and the inkconcentration of one cyan ink is 0.05 to 0.5 time that of the othermagenta ink.

9. A color ink cartridge comprising at least a yellow ink, wherein theyellow ink includes the coloring agent described in the item 1 or 4.

10. The ink cartridge described in the item 9, which further comprises;a coloring agent represented by the following general formula (M-I) asthe magenta ink; and a coloring agent represented by the followinggeneral formula (C-I) as the cyan ink:

wherein A¹ represents a residue of a 5-membered heterocyclic diazocomponent A¹-NH₂; B¹ and B² each represent a nitrogen atom, —CR¹═ or—CR²═, and when one of B¹ and B² represents a nitrogen atom, the otherrepresents —CR¹═ or —CR²═; R⁵ and R⁶ each independently represents ahydrogen atom, an aliphatic group, an aromatic group, a heterocyclicgroup, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group,a carbamoyl group, an alkyl- or arylsulfonyl group or a sulfamoyl group,which may further have a substituent group; G¹, R¹ and R² eachindependently represents a hydrogen atom, a halogen atom, an aliphaticgroup, an aromatic group, a heterocyclic group, a cyano group, acarboxyl group, a carbamoyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a heterocyclic oxycarbonyl group, an acyl group,a hydroxyl group, an alkoxyl group, an aryloxy group, a heterocyclic oxygroup, a silyloxy group, an acyloxy group, a carbamoyloxy group, analkoxy-carbonyloxy group, an aryloxycarbonyloxy group, an amino group(containing a heterocyclic amino group and an anilino group), anacylamino group, a ureido group, a sulfamoylamino group, analkoxycarbonylamino group, an aryloxycarbonylamino group, an alkyl- orarylsulfonylamino group, a heterocyclic sulfonylamino group, a nitrogroup, an alkyl- or arylthio group, an alkyl- or arylsulfonyl group, aheterocyclic sulfonyl group, an alkyl- or arylsulfinyl group, aheterocyclic sulfonyl group, a sulfamoyl group, a sulfo group or aheterocyclic thio group, which may be further substituted; and R¹ andR⁵, or R⁵ and R⁶ may combine with each other to form a 5- or 6-memberedring,

wherein X¹, X², X³ and X⁴ each independently represent —SO-Z¹, —SO₂Z¹,SO₂NR²¹R²², —CONR²¹R²² or —CO₂R²¹ in which Z¹ represents a substitutedor unsubstituted alkyl, cycloalkyl, alkenyl, aralkyl, aryl orheterocyclic group; and R²¹ and R²² each independently represent ahydrogen atom or a substituted or unsubstituted alkyl, cycloalkyl,alkenyl, aralkyl, aryl or heterocyclic group; Y¹, Y², Y³ and Y⁴ eachindependently represent a monovalent substituent; a1 to a4 and b1 to b4each independently represent an integer of from 0 to 4 indicating thenumber of substituents X¹ to X⁴ and Y¹ to Y⁴, with the proviso that a1to a4 are not 0 at the same time and when a1 to a4 and b1 to b4 eachrepresent an integer of not smaller than 2, the plurality of X¹'s toX⁴'s and Y¹'s to Y⁴'s may be the same or different; and M represents ahydrogen atom or a metal atom, or oxide, hydroxide or halide thereof.

11. An ink jet printer using the ink set as described in the item 1 or4.

12. An image recording method which comprises using the ink setdescribed in the item 1 or 4 to conduct color printing.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be further described hereinafter.

<Yellow Ink>

From the standpoint of fastness, particularly to ozone gas, the yellowdye which is a coloring agent of the invention has a forced fading rateconstant (k) of not greater than 5.0×10⁻² [hour⁻¹]), preferably notgreater than 3.0×10⁻² [hour⁻¹], more preferably not greater than1.0×10⁻² [hour⁻¹) as determined by the equation 0.8=e^(−kt) from thetime required until the reflection density of a printed matter obtainedby printing an ink for ink jet recording comprising the dye dissolvedand/or dispersed in an aqueous medium on a reflective medium reaches 80%of the initial density when the printed matter is forcedly faded usingan ozone fading tester capable of always generating 5 ppm ozone whereinthe initial density of the ink is defined by one of the values ofreflection density (D_(S)) ranging from 0.90 to 1.10 in the yellow rangeas measured with a status A filter (e.g., Type X-rite 310 TRdensitometer).

The yellow dye preferably exhibits an oxidation potential of higher than1.0 V (vs SCE), more preferably higher than 1.1 V (vs SCE), particularlyhigher than 1.2 V (vs SCE). It is particularly preferred that the kindof the yellow dye be an azo dye satisfying the aforementionedrequirements for physical properties.

The oxidation potential (Eox) can be easily measured by those skilled inthe art. For the details of the method for measuring the oxidationpotential, reference can be made to P. Delahay, “New InstrumentalMethods in Electrochemistry”, 1954, Interscience Publishers, A. J. Bardet al, “Electrochemical Methods”, 1980, John Wiley & Sons, and AkiyaFujishima, “Denki Kagaku Sokuteiho (Electrochemical Measuring Methods)”,1984, Gihodo Shuppansha.

In some detail, the measurement of oxidation potential is carried out bydissolving the test specimen in a solvent such as dimethylformamide andacetonitrile containing a supporting electrolyte such as sodiumperchlorate and tetrapropylammonium perchlorate in a concentration offrom 1×10⁻⁴ to 1×10⁻⁶ mol/l, and then measuring the test solution foroxidation potential with respect to SCE (saturated calomel electrode)using cyclic voltammetry or DC polarography. This value may deviate byscores of millivolts due to the effect of difference in potentialbetween solutions or resistivity of test solution. However, theincorporation of a standard specimen (e.g., hydroquinone) makes itpossible to assure the reproducibility of potential.

In order to unequivocally define potential, the potential (vs SCE)measured in dimethylformamide containing 0.1 mol dm⁻³ oftetrapropylammonium perchlorate as a supporting electrolyte(concentration of dye: 0.001 mol dm⁻³) using DC polarography is definedas oxidation potential of dye.

The value of Eox indicates the transferability of electrons from thespecimen to the electrode. The greater this value is (the higher theoxidation potential is), the more difficultly can be transferredelectrons from the specimen to the electrode, i.e., the more difficultlycan be oxidized the specimen. With regard to the structure of thecompound, the incorporation of electron-withdrawing group causes theoxidation potential to be higher while the incorporation ofelectron-donative group causes the oxidation potential to be lower. Inthe invention, in order to deteriorate the reactivity with ozone, whichis an electron-withdrawing agent, it is preferred that anelectron-withdrawing group be incorporated in the yellow dye skeleton tocause the oxidation potential to be higher.

The dye to be used in the invention preferably exhibits a good fastnessas well as a good hue. It is particularly preferred that the absorptionspectrum of the dye to be used in the invention have a short skirt tolonger wavelengths. Accordingly, a yellow dye having λmax of from 390 nmto 470 nm and an I(λmax+70 nm)/I(λmax) ratio of not greater than 0.2,preferably not greater than 0.1 in which I(λmax) is the absorbance atλmax and I(λmax+70 nm) is the absorbance at λmax+70 nm (hereinafterreferred to as “ratio I”) is preferred. The lower limit of the ratio Iis about 0.01. The values of λmax, etc. are determined with an aqueoussolution.

The dye satisfying these requirements for oxidation potential andabsorption characteristics is preferably one represented by thefollowing general formula (1).

However, the compound represented by the general formula (1) only needsto have λmax of from 390 nm to 470 nm and doesn't necessarily need tosatisfy the above defined oxidation potential and I(λmax+70 nm)/I(λmax)ratio. The yellow dye defined in The item 1 and the yellow dyerepresented by the general formula (1) defined in The item 4 aregenerally termed herein as “yellow dye of the invention”.A−N=N−B  (1)wherein A and B each independently represent a heterocyclic group whichmay be substituted.

The aforementioned heterocyclic group is preferably one formed by a 5-or 6-membered ring and may have a monocyclic structure or a polycyclicstructure having two or more rings condensed thereto. The aforementionedheterocyclic group may be an aromatic heterocyclic group or non-aromaticheterocyclic group. Preferred examples of the hetero atoms constitutingthe aforementioned heterocyclic group include N, O and S atoms.

Preferred examples of the heterocyclic group represented by A in thegeneral formula (1) include 5-pyrazolone, pyrazole, triazole, oxazolone,isooxazolone, barbituric acid, pyridone, pyridine, rhodanine,pyrazolinedione, pyrazolopyridone, Meldrum's acid, and condensedheterocyclic group having an aromatic hydrocarbon ring or heterocyclicgroup condensed to these heterocyclic groups. Preferred among theseheterocyclic groups are 5-pyrazolone, 5-aminopyrazole, pyridone,2,6-diaminopyridine, and pyrazoloazoles. Particularly preferred amongthese heterocyclic groups are 5-aminopyrazole, 2-hydroxy-6-pyridone,2,6-diaminopyridine, and pyrazoloazoles.

Examples of the heterocyclic group represented by B include pyridine,pyrazine, pyrimidine, pyridazine, triazine; quinoline, isoquinoline,quinazoline, cinnoline, phthaladine, quinoxaline, pyrrole, indole,furane, benzofurane, thiophene, benzothiophene, pyrazole, imidazole,benzoimidazole, triazole, oxazole, isoxazole, benzoxazole, thiazole,benzothiazole, benzothiazole, isothiazole, benzoisothiazole,thiadiazole, benzoisoxazole, pyrrolidine, piperidine, piperazine,imidazolidine, and thiazoline. Preferred among these heterocyclic groupsare pyridine, quinoline, thiophene, pyrazole, imidazole, benzoimidazole,triazole, oxazole, isoxazole, benzoxazole, thiazole, benzothiazole,isothiazole, benzoisothiazole, thiadiazole, and benzoisoxazole. Moredesirable among these heterocyclic groups are quinoline, thiophene,pyrazole, benzoxazole, benzoisoxazole, isothiazole, imidazole,benzothiazole, and thiadiazole. Particularly preferred among theseheterocyclic groups are pyrazole, benzoxazole, benzoxazole, imidazole,1,2,4-thiadiazole, and 1,3,4-thiadiazole.

Examples of the substituents on A and B include halogen atoms, alkylgroups, cycloalkyl groups, aralkyl groups, alkenyl groups, alkinylgroups, aryl groups, heterocyclic groups, cyano groups, hydroxyl groups,nitro groups, alkoxy groups, aryloxy groups, silyloxy groups,heterocyclic oxy groups, acyloxy groups, carbamoyloxy groups,alkoxycarbonyloxy groups, aryloxycarbonyloxy groups, amino groups,acylamino groups, aminocarbonylamino groups, alkoxycarbonylamino groups,aryloxycarbonylamino groups, sulfamoylamino groups, alkylsulfonylaminogroups, arylsulfonylamino groups, mercapto groups, alkylthio groups,arylthio groups, heterocyclic thio groups, sulfamoyl groups,alkylsulfinyl groups, arylsulfinyl groups, alkylsulfonyl groups,arylsulfonyl groups, acyl groups, aryloxycarbonyl groups, alkoxycarbonylgroups, carbamoyl groups, imide groups, phosphino groups, phosphinylgroups, phosphinyloxy groups, phosphinylamino groups, silyl groups, andionic hydrophilic groups.

The dye of the general formula (1), if used as a water-soluble dye,preferably has at least one ionic hydrophilic group incorporated thereinper molecule. Examples of the ionic hydrophilic group include sulfogroups, carboxyl groups, phosphono groups, and quaternary ammoniumgroups. Preferred among these ionic hydrophilic groups are carboxylgroups, phosphono groups, and sulfo groups. Particularly preferred amongthese ionic hydrophilic groups are carboxyl groups and sulfo groups. Thecarboxyl groups, phosphono groups and sulfo groups may be in the form ofsalt. Examples of the counter ion forming the salt include ammonium ion,alkaline metal ion (e.g., lithium ion, sodium ion, potassium ion), andorganic cation (e.g., tetramethylammonium ion, tetramethylguanidium ion,tetramethylphosphonium ion). Preferred among these counter ions arealkaline metal salts.

Preferred among these dyes represented by the general formula (1) arethose of the following general formulae (2), (3) and (4).

wherein R1 and R3 each represent a hydrogen atom, cyano group, alkylgroup, cycloalkyl group, aralkyl group, alkoxy group, alkylthio group,arylthio group, aryl group or ionic hydrophilic group; R2 represents ahydrogen atom, alkyl group, cycloalkyl group, aralkyl group, carbamoylgroup, acyl group, aryl group or heterocyclic group; and R4 represents aheterocyclic group.

wherein R5 represents a hydrogen atom, cyano group, alkyl group,cycloalkyl group, aralkyl group, alkoxy group, alkylthio group, arylthiogroup, aryl group or ionic hydrophilic group; Za represents —N═, —NH— or—C(R11)=; Zb and Zc each independently represent —N═ or —C(R11) in whichR11 represents a hydrogen atom or non-metallic substituent; and R6represents a heterocyclic group.

wherein R7 and R9 each independently represent a hydrogen atom, cyanogroup, alkyl group, cycloalkyl group, aralkyl group, aryl groupsalkylthio group, arylthio group, alkoxycarbonyl group, carbamoyl groupor ionic hydrophilic group; R8 represents a hydrogen atom, halogen atom,alkyl group, alkoxy group, aryl group, aryloxy group, cyano group,acylamino group, sulfonylamino group, alkoxycarbonylamino group, ureidegroup, alkylthio group, arylthio group, alkoxycarbonyl group, carbamoylgroup, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, acylgroup, amino group, hydroxy group or ionic hydrophilic group; and R10represents a heterocyclic group.

In the general formulae (2), (3) and (4), the alkyl groups representedby R1, R2, R3, R5, R7, R8 and R9 contain a substituted or unsubstitutedalkyl group. These alkyl groups each preferably have from 1 to 20 carbonatoms. Examples of the aforementioned substituents include hydroxylgroups, alkoxy groups, cyano groups, halogen atoms, and ionichydrophilic groups. Examples of the alkyl groups include methyl, ethyl,butyl, isopropyl, t-butyl, hydroxyethyl, methoxyethyl, cyanoethyl,trifluoromethyl, 3-sulfopropyl, and 4-sulfobutyl.

The cycloalkyl groups represented by R1, R2, R3, R5, R7, R8 and R9include a substituted or unsubstituted cycloalkyl group. Thesecycloalkyl groups each preferably have from 5 to 12 carbon atoms.Examples of the substituents on the cycloalkyl group include ionichydrophilic groups. Examples of the cycloalkyl group include cyclohexylgroups.

Examples of the aralkyl groups represented by R1, R2, R3, R5, R7, R8 andR9 include substituted and unsubstituted aralkyl groups. These aralkylgroups each preferably have from 7 to 20 carbon atoms. Examples of thesubstituents on the aralkyl group include ionic hydrophilic groups.Examples of the aralkyl group include benzyl, and 2-phenethyl.

Examples of the aryl groups represented by R1, R2, R3, R5, R7, R8 and R9include substituted and unsubstituted aryl groups. These aryl groupseach preferably have from 6 to 20 carbon atoms. Examples of thesubstituents on the aryl group include alkyl groups, alkoxy groups,halogen atoms, alkylamino groups, and ionic hydrophilic groups. Examplesof the aryl group include phenyl, p-tollyl, p-methoxyphenyl,o-chlorophenyl, and m-(3-sulfopropylamino)phenyl.

Examples of the alkylthio groups represented by R1, R2, R3, R5, R7, R8and R9 include substituted and unsubstituted alkylthio groups. Thesealkylthio groups each preferably have from 1 to 20 carbon atoms.Examples of the substituents on the alkylthio group include ionichydrophilic groups. Examples of the alkylthio group include methylthio,and ethylthio group.

Examples of the arylthio groups represented by R1, R2, R3, R5, R7, R8and R9 include substituted and unsubstituted arylthio groups. Thesearylthio groups each preferably have from 6 to 20 carbon atoms. Examplesof the substituents on the arylthio group include alkyl groups, andionic hydrophilic groups. Examples of the arylthio group includephenylthio, and p-tolylthio group.

The heterocyclic groups represented by R2 and by R22 described latereach preferably are a 5- or 6-membered heterocyclic group which may befurther condensed. Preferred examples of the heteroatoms constitutingthe heterocyclic group include N, S and O atoms. The heterocyclic groupsmay be aromatic or non-aromatic. These heterocyclic groups may befurther substituted. Examples of the substituents on the heterocyclicgroup include those listed with reference to the aryl group describedlater. Preferred examples of the heterocyclic groups include a6-membered nitrogen-containing aromatic heterocyclic group. Particularlypreferred examples of such a 6-membered nitrogen-containing aromaticheterocyclic group include triazine, pyrimidine, and phthaladine.

Examples of the halogen atom represented by R8 include fluorine atom,chlorine atom, and bromine atom.

Examples of the alkoxy groups represented by R1, R3, R5 and R8 includesubstituted and unsubstituted alkoxy groups. These alkoxy groups eachpreferably have from 1 to 20 alkoxy groups. Examples of the substituentsinclude hydroxyl groups, and ionic hydrophilic groups. Examples of thealkoxy groups include methoxy, ethoxy, isopropoxy, methoxyethoxy,hydroxyethoxy, and 3-carboxypropoxy.

Examples of the aryloxy group represented by RR include substituted andunsubstituted aryloxy groups. These aryloxy groups each preferably havefrom 6 to 20 carbon atoms. Examples of the substituents on the aryloxygroup include alkoxy groups, and ionic hydrophilic groups. Examples ofthe aryloxy groups include phenoxy, p-methoxyphenoxy, ando-methoxyphenoxy.

Examples of the acylamino group represented by R8 include substitutedand unsubstituted acylamino groups. These acylamino groups eachpreferably have from 2 to 20 carbon atoms. Examples of the substituentson the acylamino group include ionic hydrophilic groups. Examples of theacylamino group include acetamide, propionamide, benzamide, and3,5-disulfobenzamide.

Examples of the sulfonylamino group represented by R8 includesubstituted and unsubstituted sulfonylamino groups. These sulfonylaminogroups each preferably have from 1 to 20 carbon atoms. Examples of thesulfonylamino group include methylsulfonylamino, and ethylsulfonylamino.

Examples of the alkoxycarbonylamino group represented by R8 includesubstituted and unsubstituted alkoxycarbonylamino groups. Thesealkoxycarbonylamino groups each preferably have from 2 to 20 carbonatoms. Examples of the substituents on the alkoxycarbonylamino groupinclude ionic hydrophilic groups. Examples of the alkoxycarbonylaminogroup include ethoxycarbonylamino. Examples of the ureide grouprepresented by R8 include substituted and unsubstituted ureide groups.These ureide groups each preferably have from 1 to 20 carbon atoms.Examples of the substituents on the ureide group include alkyl groups,and aryl groups. Examples of the ureide group include 3-methylureide,3,3-dimethylureide, and 3-phenylureide.

Examples of the alkoxycarbonyl groups represented by R7, R8 and R9include substituted and unsubstituted alkoxycarbonyl groups. Thesealkoxycarbonyl groups each preferably have from 2 to 20 carbon atoms.Examples of the substituents on the alkoxycarbonyl group include ionichydrophilic groups. Examples of the alkoxycarbonyl group includemethoxycarbonyl, and ethoxycarbonyl.

Examples of the carbamoyl groups represented by R2, R7, R8 and R9include substituted and unsubstituted carbamoyl groups. Examples of thesubstituents on the carbamoyl group include alkyl groups. Examples ofthe carbamoyl group include methylcarbamoyl group, and dimethylcarbamoylgroup.

Examples of the sulfamoyl group represented by R8 include substitutedand unsubstituted sulfamoyl groups. Examples of the substituents on thesulfamoyl group include alkyl groups. Examples of the sulfamoyl groupinclude dimethylsulfamoyl group, and di-(2-hydroxyethyl)sulfamoyl group.

Examples of the alkylsulfinyl and arylsulfonyl groups represented by R8include methylsulfonyl, and phenylsulfonyl.

Examples of the acyl groups represented by R2 and R8 include substitutedand unsubstituted acyl groups. These acyl groups each preferably havefrom 1 to 20 carbon atoms. Examples of the substituents on the acylgroup include ionic hydrophilic groups. Examples of the acyl groupinclude acetyl, and benzoyl.

Examples of the amino group represented by R8 include substituted andunsubstituted amino groups. Examples of the substituents on the aminogroup include alkyl groups, aryl groups, and heterocyclic groups.Examples of the amino group include methylamino, diethylamino, anilino,and 2-chloroanilino.

The heterocyclic groups represented by R4, R6 and R10 are the same asthe heterocyclic groups represented by B in the general formula (1)which may be substituted. Preferred examples of the heterocyclic groupsinclude those listed with reference to B in the general formula (1).Even more desirable examples of the heterocyclic groups include thoselisted with reference to B in the general formula (1). Particularlypreferred examples of the heterocyclic groups include those listed withreference to B in the general formula (1). Examples of the substituentson the heterocyclic group include ionic hydrophilic groups, C₁-C₁₂alkyl, aryl and arylthio groups, halogen atoms, cyano groups, sulfamoylgroups, sulfonamide groups, carbamoyl groups, and acylamino groups.These alkyl and aryl groups may further contain substituents.

In the general formula (3), Za represents —N═, —NH— or —C(R11)=. Zb andZc each independently represent —N═ or —C(R11)= in which R11 representsa hydrogen atom or non-metallic substituent. Preferred examples of thenon-metallic substituent represented by R11 include cyano groups,cycloalkyl groups, aralkyl groups, aryl groups, alkylthio groups,arylthio groups, and ionic hydrophilic groups. These substituents eachhave the same meaning as those represented by R1. Preferred examples ofthese substituents include those listed with reference to R1. Examplesof the skeleton of the heterocyclic group composed of two 5-memberedrings contained in the general formula (3) will be given below.

Examples of the substituents on the aforementioned substituents whichmay further have substituents include substituents which may substitutethe heterocyclic groups A and B in the general formula (1).

The dyes represented by the general formulae (2) to (4), if used as awater-soluble dye, preferably contain at least one ionic hydrophilicgroup per molecule. Besides the dyes of the general formulae (2) to (4)wherein at least any one of R1, R2, R3, R5, R7, R8 and R9 is an ionichydrophilic group, dyes of the general formulae (2) to (4) wherein R1 toR1 further contain an ionic hydrophilic group as a substituent may beused.

Preferred among the dyes of the general formulae (2), (3) and (4) arethose represented by the general formula (2). Particularly preferredamong the dyes of the general formula (2) is one represented by thefollowing general formula (2-1).

wherein R²¹ and R²³ each represent a hydrogen atom, alkyl group,cycloalkyl group, alkoxy group or aryl group; R²² represents an arylgroup or heterocyclic group; and one of X and Y represents a nitrogenatom and the other represents —CR²⁴ in which R24 represents a hydrogenor halogen atom or a cyano, alkyl, alkylthio, alkylsulfonyl,alkylsulfinyl, alkyloxycarbonyl, carbamoyl, alkoxy, aryl, arylthio,arylsulfonyl, arylsulfinyl, aryloxy or acylamino group which may befurther substituted.

In the general formula (2-1), R²² is preferably a heterocyclic group(e.g., triazine ring, pyrimidine ring), more preferably a triazine ringor pyrimidine ring, particularly atriazine ring. The dye of the generalformula (2-1) preferably has an ionic hydrophilic group. Morepreferably, R²² is a heterocyclic group (e.g., triazine ring, pyrimidinering).

Specific examples of the dye to be used in the invention will be givenbelow, but the dye to be used in the invention is not limited thereto.These compounds can be synthesized according to JP-A-2-24191,JP-A-2001-279145, and Japanese Patent Application No. 2000-124832.

R YI-18 CH₃ YI-19 C₃H₆SO₃Na YI-20 H YI-21 C₂H₄CN YI-22

YI-23

YI-24

YI-25

YI-26

YI-27

R YI-28 CH₃ YI-29

YI-30 OC₂H₅

R YI-31

YI-32 CH₃ YI-33 SC₂H₄SO₃Na YI-34 SO₂C₂H₄SO₃Na

R YI-35 H YI-36 CH₃ YI-37

R YI-38 COOC₄H₉ YI-39 CON(C₄H₉)₂ YI-40 SO₂NHC₁₂H₂₅ YI-41 OC₈H₁₇

R R′ YI-42 CON(C₄H₉)₂ H YI-43 COOC₈H₁₇ H YI-44 CON(C₄H₉)₂

YI-45 CON(C₄H₉)₂ CH₃ YI-46 H

YI-47 H SC₈H₁₇

R YI-48 —NHC₂H₄COOK YI-49 —NHC₂H₄SO₃Na YI-50

YI-51

YI-52

YI-53 —N

CH₂COONa)₂ YI-54

YI-55

YI-56 —NHC₆H₁₃ YI-57 —N(C₄H₉)₂

Ar YI-58

YI-59

YI-60

YI-61

YI-62

YI-63

YI-64

YI-65

R R′ YI-66 Ph H YI-67 OC₂H₅ C₂H₅ YI-68 CH₃ H YI-69 t-C₄H₉ H YI-70 t-C₄H₉—C₂H₄COOH YI-71

R YI-72 H YI-73 OCH₃ YI-74 OH YI-75 SO₃Na YI-76 F YI-77

R¹ R² R³ YI-78 Cl Cl Cl YI-79 Cl Cl F YI-80 Cl —CONHPh Cl

R¹ R² R³ YI-81 F H H YI-82 Cl H F

R¹ R² R³ YI-83 H F F YI-84 F F H

R YI-85 H YI-86 CH₃ YI-87 Ph YI-88 SCH₂COONa YI-89 SC₂H₅ YI-90 SC₄H₉-nYI-91 SCH₂CHMe₂ YI-92 SCHMeEt YI-93 SC₄H₉-t YI-94 SC₇H₁₅-n YI-95SC₂H₄OC₂H₅ YI-96 SC₂H₄OC₄H₉-n YI-97 SCH₂CF₃

R YI-98 —NHC₂H₂COOK YI-99 —NHC₂H₄SO₃Na YI-100

YI-101

YI-102

YI-103

YI-104 —NHC₆H₁₃-n YI-105 —N(C₄H₉-n)₂ YI-106 —N

CH₂COONa)₂ YI-107

YI-108

The ink for ink jet recording of the invention preferably contains ayellow dye of the invention in an amount of from 0.2% to 20% by weight,more preferably from 0.5% to 15% by weight.

<Magenta Ink>

The coloring agent represented by the general formula (M-I) which ispreferably used in the invention will be described hereinafter.

In the general formula (M-I), A¹ represents a 5-membered heterocyclicgroup.

B¹ and B² represent ═CR¹— or —CR²═, respectively. Alternatively, one ofB¹ and B² represents a nitrogen atom and the other represents ═CR¹— or—CR²═. R⁵ and R⁶ each independently represent a hydrogen atom orsubstituent. Examples of the substituent represented by R⁵ and R⁶include aliphatic groups, aromatic groups, heterocyclic groups, acylgroups, alkoxycarbonyl groups, aryoxycarbonyl groups, carbamoyl groups,alkylsulfinyl groups, arylsulfonyl groups, and sulfamoyl groups. Thehydrogen atoms in these substituents may be substituted.

G¹, R¹ and R² each independently represent a hydrogen atom orsubstituent. Examples of the substituents represented by G¹, R¹ and R²include halogen atoms, aliphatic groups, aromatic groups, heterocyclicgroups, cyano groups, carboxyl groups, carbamoyl groups, alkoxycarbonylgroups, aryloxycarbonyl groups, heterocyclic oxycarbonyl groups, acylgroups, hydroxy groups, alkoxy groups, aryloxy groups, heterocyclic oxygroups, silyloxy groups, acyloxy groups, carbamoyloxy groups,alkoxycarbonyloxy groups, aryloxycarbonyloxy groups, amino groups(including alkylamino groups, arylamino groups and heterocyclic aminogroups), acylamino groups, ureide groups, sulfamoylamino groups,alkoxycarbonylamino groups, aryloxycarbonylamino groups,alkylsulfonylamino groups, arylsulfonylamino groups, heterocyclicsulfonylamino groups, nitro groups, alkylthio groups, arylthio groups,heterocyclic thio groups, alkylsulfonyl groups, arylsulfonyl groups,heterocyclic sulfonyl groups, alkylsulfinyl groups, arylsulfinyl groups,heterocyclic sulfinyl groups, sulfamoyl groups, and sulfo groups. Thehydrogen atoms in these substituents may be substituted.

R¹ and R⁵ or R⁵ and R⁶ may be connected to each other to form a 5- or6-membered ring.

The dye of the general formula (M-1) will be further describedhereinafter.

In the general formula (M-1), A¹ represents a 5-membered heterocyclicgroup. Examples of the hetero atoms constituting the heterocyclic groupinclude N, O and S atoms. The heterocyclic group represented by A¹ ispreferably a nitrogen-containing 5-membered heterocyclic group to whichaliphatic or aromatic rings or other heterocyclic groups may becondensed. Preferred examples of the heterocyclic group include pyrazolerings, imidazole rings, thiazole rings, isothiazole rings, thiadiazolerings, benzothiadiazole rings, benzoxazole rings, and benzoisothiazolerings. These heterocyclic groups may further contain substituents.Preferred among these substituents are pyrazole ring, imidazole ring,isothiazole ring, thiadiazole ring and benzothiazole represented by thefollowing general formulae (a) to (f).

In the general formulae (a) to (f), R⁷ to R²⁰ represent the samesubstituents as represented by G¹, R¹ and R² in the general formula(M-I).

Preferred among the substituents represented by the general formulae (a)to (f) are pyrazole ring and isothiazole ring represented by the generalformulae (a) and (b). Particularly preferred among these substituents ispyrazole ring represented by the general formula (a).

In the general formula (M-I), B¹ and B² represent —CR¹— and —CR²═,respectively. Alternatively, one of B¹ and B² represents a nitrogen atomand the other represents —CR¹— or —CR²═. Preferably, B¹ and B² represent═CR¹— and —CR²═, respectively.

R⁵ and R⁶ each independently represent a hydrogen atom or a substituent.Examples of the substituents represented by R⁵ and R⁶ include aliphaticgroups, aromatic groups, heterocyclic groups, acyl groups,alkoxycarbonyl groups, aryloxycarbonyl groups, carbamoyl groups,alkylsulfonyl groups, arylsulfonyl groups, and sulfamoyl groups. Thehydrogen atoms in these substituents may be substituted.

Preferred among the groups represented by R⁵ and R⁶ are hydrogen atom,aliphatic groups, aromatic groups, heterocyclic groups, acyl groups,alkylsulfonyl groups and arylsulfonyl groups. More desirable among thesegroups are hydrogen atom, aromatic groups, heterocyclic groups, acylgroups, alkylsulfonyl groups and arylsulfonyl groups. Most desirableamong these groups are hydrogen atom, aryl groups and heterocyclicgroups. The hydrogen atoms in these substituents may be substituted.However, R⁵ and R⁶ are not a hydrogen atom at the same time.

G¹, R¹ and R² each independently represent a hydrogen atom or asubstituent. Examples of the substituents represented by G¹, R¹ and R²include a halogen atom or an aliphatic, aromatic, heterocyclic, cyano,carboxyl, carbamoyl, alkoxycarbonyl, aryloxycarbonyl, heterocyclicoxycarbonyl, acyl, hydroxyl, alkoxy, aryloxy, heterocyclic oxy,silyloxy, acyloxy, carbamoyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy,amino (including heterocyclic amino group and anilino group), acylamino,ureide, sulfamoylamino, alkoxycarbonylamino, aryloxycarbonylamino,alkylsulfonylamino, arylsulfonylamino, heterocyclic sulfonylamino,nitro, alkylthio, arylthio, heterocyclic thio, alkylsulfonyl,arylsulfonyl, heterocyclic sulfonyl, alkylsulfinyl, arylsulfinyl,heterocyclic sulfinyl, sulfamoyl or sulfo group. The hydrogen atoms inthese substituents may be substituted.

Preferred among the groups represented by G¹ are hydrogen atom, halogenatom, aliphatic groups, aromatic groups, hydroxy groups, alkoxy groups,aryloxy groups, acyloxy groups, heterocyclic oxy groups, amino groups(including alkylamino group, arylamino group, heterocyclic amino group),acylamino groups, ureide groups, sulfamoylamino groups,alkoxycarbonylamino groups, aryloxycarbonylamino groups, alkylthiogroups, arylthio groups, and heterocyclic thio groups. More desirableamong these groups are hydrogen atom, halogen atom, alkyl groups,hydroxy groups, alkoxy groups, aryloxy groups, acyloxy groups, aminogroups, and acylamino groups. Most desirable among these groups arehydrogen atom, amino groups (preferably anilino group), and acylaminogroups. The hydrogen atoms in these substituents may be substituted.

Preferred among the groups represented by R¹ and R² are hydrogen atom,alkyl groups, halogen atom, alkoxycarbonyl groups, carboxyl groups,carbamoyl groups, hydroxy groups, alkoxy groups, and cyano groups. Thehydrogen atoms in these substituents may be substituted.

R¹ and R⁵ or R⁵ and R⁶ may be connected to each other to form a 5- or6-membered ring.

Examples of the substituents on A¹ or on the substituents by which thesubstituents of R¹, R², R⁵ and G are substituted include those listedwith reference to G, R¹ and R².

The dye of the general formula (M-I) of the invention, if it iswater-soluble, preferably has an ionic hydrophilic group on any positionon A¹, R¹, R², R⁵, R⁶ and G¹ as a substituent. Examples of the ionichydrophilic group which is a substituent include sulfo groups, carboxylgroups, phosphono groups, and quaternary ammonium groups. Preferredamong the ionic hydrophilic groups are carboxyl groups, phosphonogroups, and sulfo groups. Particularly preferred among these ionichydrophilic groups are carboxyl groups and sulfo groups. The carboxyl,phosphono and sulfo groups may be in the form of salt. Examples of thecounter ion constituting the salt include ammonium ion, alkaline metalion (e.g., lithium ion, sodium ion, potassium ion), and organic cation(e.g., tetramethyl ammonium ion, tetramethyl guanidium ion, tetramethylphosphonium ion).

The terms (substituents) used herein will be described hereinafter.These terms are common to all different signs in the following generalformula (M-I) and the general formula (M-Ia) described later.

Examples of the halogen atom include fluorine atom, chlorine atom andbromine atom.

The term “aliphatic group” as used herein is meant to include an alkylgroup, substituted alkyl group, alkenyl group, substituted alkenylgroup, alkinyl group, substituted alkinyl group, aralkyl group, andsubstituted aralkyl group. The term “substituted” as used in“substituted alkyl group” herein is meant to indicate that the hydrogenatoms present in “alkyl group”, etc. are substituted by the substituentslisted above with reference to G¹, R¹ and R².

The aliphatic group may have branches or may form a ring. The aliphaticgroup preferably has from 1 to 20 carbon atoms, more preferably from 1to 16 carbon atoms. The aryl moiety of the aralkyl group or substitutedaralkyl group is preferably a phenyl group or naphthyl group,particularly a phenyl group. Examples of the aliphatic group includemethyl group, ethyl group, butyl group, isopropyl group, t-butyl group,hydroxyethyl group, methoxyethyl group, cyanoethyl group,trifluoromethyl group, 3-sulfopropyl group, 4-sulfobutyl group,cyclohexyl group, benzyl group, 2-phenethyl group, vinyl group, andallyl group.

The term “aromatic group” as used herein is meant to include an arylgroup and substituted aryl group. The aryl group is preferably a phenylgroup or naphthyl group, particularly a phenyl group. The aromatic grouppreferably has from 6 to 20 carbon atoms, more preferably from 6 to 16carbon atoms.

Examples of the aromatic group include phenyl group, p-tollyl group,p-methoxyphenyl group, o-chlorophenyl group, andm-(3-sulfopropylamino)phenyl group.

The term “heterocyclic group” as used herein is meant to includesubstituted heterocyclic groups. The heterocyclic group may havealiphatic or aromatic rings or other heterocyclic groups condensedthereto. The heterocyclic group is preferably a 5- or 6-memberedheterocyclic group. Examples of the substituents on the heterocyclicgroup include aliphatic groups, halogen atoms, alkylsulfonyl groups,arylsulfonyl groups, acyl groups, acylamino groups, sulfamoyl groups,carbamoyl groups, and ionic hydrophilic groups. Examples of theheterocyclic group include 2-pyridyl group, 2-chenyl group, 2-thiazolylgroup, 2-benzothiazolyl group, 2-benzoxazolyl group, and 2-furyl group.

The term “carbamoyl group” as used herein is meant to includesubstituted carbamoyl groups. Examples of the substituents on thecarbamoyl group include alkyl groups. Examples of the carbamoyl groupinclude methylcarbamoyl group, and dimethylcarbamoyl group.

The term “alkoxycarbonyl group” as used herein is meant to includesubstituted alkoxycarbonyl groups. The alkoxycarbonyl group preferablyhas from 2 to 20 carbon atoms. Examples of the substituents on thealkoxycarbonyl group include ionic hydrophilic groups. Examples of thealkoxy carbonyl group include methoxycarbonyl group, and ethoxycarbonylgroup.

The term “aryloxycarbonyl group” as used herein is meant to includesubstituted aryloxycarbonyl groups. The aryloxycarbonyl group preferablyhas from 7 to 20 carbon atoms. Examples of the substituents on thearyloxycarbonyl group include ionic hydrophilic groups. Examples of thearyloxycarbonyl group include phenoxycarbonyl group.

The term “heterocyclic oxycarbonyl group” as used herein is meant toinclude substituted heterocyclic oxycarbonyl groups. Examples of theheterocyclic group include those listed above with reference to theheterocyclic group. The heterocyclic oxycarbonyl group preferably hasfrom 2 to 20 carbon atoms. Examples of the substituents on theheterocyclic oxycarbonyl group include ionic hydrophilic groups.Examples of the heterocyclic oxycarbonyl group include2-pyridyloxycarbonyl group.

The term “acyl group” as used herein is meant to include substitutedacyl groups. The acyl group preferably has from 1 to 20 carbon atoms.Examples of the substituents on the acyl group include ionic hydrophilicgroups. Examples of the acyl group include acetyl group, and benzoylgroup.

The term “alkoxy group” as used herein is meant to include substitutedalkoxy groups. The alkoxy group preferably has from 1 to 20 carbonatoms. Examples of the substituents on the alkoxy group include alkoxygroups, hydroxyl groups, and ionic hydrophilic groups. Examples of thealkoxy group include methoxy group, ethoxy group, isopropoxy group,methoxyethoxy group, hydroxyethoxy group, and 3-carboxypropoxy group.

The term “aryloxy group” as used herein is meant to include substitutedaryloxy groups. The aryoxy group preferably has from 6 to 20 carbonatoms. Examples of the substituents on the aryloxy group include alkoxygroups, and ionic hydrophilic groups. Examples of the aryloxy groupinclude phenoxy group, p-methoxyphenoxy group, and o-methoxyphenoxygroup.

The term “heterocyclic oxy group” as used herein is meant to includesubstituted heterocyclic oxy groups. Examples of the heterocyclic groupinclude those listed above with reference to the heterocyclic group. Theheterocyclic oxy group preferably has from 2 to 20 carbon atoms.Examples of the substituents on the heterocyclic oxy group include alkylgroups, alkoxy groups, alkoxy groups, and ionic hydrophilic groups,Examples of the heterocyclic oxy group include 3-pyridyloxy group, and3-chenyloxy group.

The silyloxy group is preferably a C₁-C₂₀ silyloxy group having asubstituted aliphatic or aromatic group. Examples of the silyloxy groupinclude trimethylsilyloxy, and diphenylmethylsilyloxy.

The term “acyloxy group” as used herein is meant to include substitutedacyloxy groups. The acyloxy group preferably has from 1 to 20 carbonatoms. Examples of the substituents on the acyloxy group include ionichydrophilic groups. Examples of the acryloxy group include acetoxygroup, and benzoyloxy group.

The term “carbamoyloxy group” as used herein is meant to includesubstituted carbamoyloxy groups. Examples of the substituents on thecarbamoyloxy group include alkyl groups. Examples of the carbamoyloxygroup include N-methylcarbamoyloxy group.

The term “alkoxycarbonyloxy group” as used herein is meant to includesubstituted alkoxycarbonyloxy groups. The alkoxycarbonyloxy grouppreferably has from 2 to 20 carbon atoms. Examples of thealkoxycarbonyloxy group include methoxycarbonyloxy group, andisopropoxycarbonyloxy group.

The term “aryloxycarbonyloxy group” as used herein is meant to includesubstituted aryloxycarbonyloxy groups. The aryloxycarbonyloxy preferablyhas from 7 to 20 carbon atoms. Examples of the aryloxycarbonyloxy groupinclude phenoxycarbonyloxy group.

The term “amino group” as used herein is meant to include substitutedamino groups. Examples of the substituents on the amino group includealkyl groups, aryl groups, and heterocyclic groups. The alkyl, aryl andheterocyclic groups may further have substituents. The term “alkylaminogroup” as used herein is meant to include substituted alkylamino groups.The alkylamino group preferably has from 1 to 20 carbon atoms. Examplesof the substituents on the alkylamino group include ionic hydrophilicgroups. Examples of the alkylamino group include methylamino group, anddiethylamino group.

The term “arylamino group” as used herein is meant to includesubstituted arylamino groups. The arylamino group preferably has from 6to 20 carbon atoms. Examples of the substituents on the arylamino groupinclude halogen atoms, and ionic hydrophilic groups. Examples of thearylamino group include phenylamino group, and 2-chlorophenylaminogroup.

The term “heterocyclic amino group” as used herein is meant to includesubstituted heterocyclic amino groups. Examples of the heterocyclicgroup include those listed above with reference to the heterocyclicgroup. The heterocyclic amino group preferably has from 2 to 20 carbonatoms. Examples of the substituents on the heterocyclic amino groupinclude alkyl groups, halogen atoms, and ionic hydrophilic groups.

The term “acylamino group” as used herein is meant to includesubstituted acylamino groups. The acylamino group preferably has from 2to 20 carbon atoms. Examples of the substituents on the acylamino groupinclude ionic hydrophilic groups. Examples of the acrylamino groupinclude acetylamino group, propionylamino group, benzoylamino group,N-phenylacetylamino group, and 3,5-disulfobenzoylamino group.

The term “ureide group” as used herein is meant to include substitutedureide groups. The ureide group preferably has from 1 to 20 carbonatoms. Examples of the substituents on the ureide group include alkylgroup, and aryl group. Examples of the ureide group include3-methylureide group, 3,3-dimethylureide group, and 3-phenylureidegroup.

The term “sulfamoylamino group” as used herein is meant to includesubstituted sulfamoylamino groups. Examples of the substituents on thesulfamoylamino group include alkyl groups. Examples of thesulfamoylamino group include N,N-dipropylsulfamoylamino group.

The term “alkoxycarbonylamino group” as used herein is meant to includesubstituted alkoxycarbonylamino groups. The alkoxycarbonylamino grouppreferably has from 2 to 20 carbon atoms. Examples of the substituentson the alkoxycarbonylamino group include ionic hydrophilic groups.Examples of the alkoxycarbonylamino group include ethoxycarbonylaminogroup.

The term “aryoxycarbonylamino group” as used herein is meant to includesubstituted aryloxycarbonylamino groups. The aryloxycarbonylamino grouppreferably has from 7 to 20 carbon atoms. Examples of the substituentson the aryloxycarbonylamino group include ionic hydrophilic groups.Examples of the aryloxycarbonylamino group include phenoxycarbonylaminogroup.

The term “alkylsulfonylamino group and arylsulfonylamino group” as usedherein is meant to include substituted alkylsulfonylamino groups andsubstituted or unsubstituted arylsulfonylamino groups, respectively. Thealkylsulfonylamino group and arylsulfonylamino group each preferablyhave from 1 to 20 carbon atoms and from 7 to 20 carbon atoms,respectively. Examples of the substituents on the alkylsulfonylaminogroup and arylsulfonylamino group include ionic hydrophilic groups.Examples of the alkylsulfonylamino group and arylsulfonylamino groupinclude methylsulfonylamino group, N-phenyl-methylsulfonylamino group,phenylsulfonylamino group, and 3-carboxyphenylsulfonylamino group.

The term “heterocyclic sulfonylamino group” as used herein is meant toinclude substituted heterocyclic sulfonylamino groups. The heterocyclicsulfonylamino group preferably has from 1 to 12 carbon atoms. Examplesof the substituents on the heterocyclic sulfonylamino group includeionic hydrophilic groups. Examples of the heterocyclic sulfonylaminogroup include 2-chenylsulfonylamino group, and 3-pyridylsulfonylaminogroup.

The term “alkylthio group, arylthio group and heterocyclic thio group”as used herein is meant to include substituted alkyl groups, substitutedarylthio groups and substituted heterocyclic thio groups, respectively.Examples of the heterocyclic group include those listed above withreference to the heterocyclic group. The alkylthio group, arylthio groupand heterocyclic thio group each preferably have from 1 to 20 carbonatoms. Examples of the substituents on the alkylthio group, arylthiogroup and heterocyclic thio group include ionic hydrophilic groups,Examples of the alkylthio group, arylthio group and heterocyclic thiogroup include methylthio group, phenylthio group, and 2-pyridylthiogroup.

The term “alkylsulfonyl group and arylsulfonyl group” as used herein ismeant to include substituted alkylsulfonyl groups and substitutedarylsulfonyl groups, respectively. Examples of the alkylsulfonyl groupand arylsulfonyl group include methylsulfonyl group and phenylsulfonylgroup.

The term “heterocyclic sulfonyl group” as used herein is meant toinclude substituted heterocyclic sulfonyl groups. Examples of theheterocyclic group include those listed above with reference to theheterocyclic group. The heterocyclic sulfonyl group preferably has from1 to 20 carbon atoms. Examples of the substituents on the heterocyclicsulfonyl group include ionic hydrophilic groups. Examples of theheterocyclic sulfonyl group include 2-chenylsulfonyl group and3-pyridylsulfonyl group.

The term “alkylsulfinyl group and arylsulfinyl group” as used herein ismeant to include substituted alkylsulfinyl groups and substitutedarylsulfinyl groups, respectively. Examples of the alkylsulfinyl groupand arylsulfinyl group include methylsulfinyl group and phenylsulfinylgroup.

The term “heterocyclic sulfinyl group” as used herein is meant toinclude substituted heterocyclic sulfinyl groups. Examples of theheterocyclic group include those listed above with reference to theheterocyclic group. The heterocyclic sulfinyl group preferably has from1 to 20 carbon atoms. Examples of the substituents on the heterocyclicsulfinyl group include ionic hydrophilic groups. Examples of theheterocyclic sulfinyl group include 4-pyridylsulfinyl group.

The term “sulfamoyl group” as used herein is meant to includesubstituted sulfamoyl groups, Examples of the substituents on thesulfamoyl group include alkyl groups. Examples of the sulfamoyl groupinclude dimethylsulfamoyl group and di-(2-hydroxyethyl)sulfamoyl group.

A particularly preferred structure of the dye of the invention is onerepresented by the following general formula (M-Ia).

In the general formula (M-I), R¹, R², R and R⁶ are as defined in thegeneral formula (M-I).

R³ and R⁴ each independently represent a hydrogen atom or substituent.Examples of the substituent include aliphatic groups, aromatic groups,heterocyclic groups, acyl groups, alkoxycarbonyl groups, aryloxycarbonylgroups, carbamoyl groups, alkylsulfonyl groups, arylsulfonyl groups, andsulfamoyl groups, preferred among these groups are hydrogen atom,aromatic groups, heterocyclic groups, acyl groups, alkylsulfonyl groups,and arylsulfonyl groups. Particularly preferred among these groups arehydrogen atom, aromatic groups, and heterocyclic groups.

Z¹ represents an electron-withdrawing group having a Hammett'ssubstituent constant σp of not smaller than 0.20. Z¹ is preferably anelectron-withdrawing group having a Hammett's substituent constant op ofnot smaller than 0.30, more preferably not smaller than 0.45,particularly not smaller than 0.60. However, the Hammett's substituentconstant op of the electron-withdrawing group is preferably not greaterthan 1.0. Specific preferred examples of the substituents includeelectron-withdrawing substituents described later. Preferred among theseelectron-withdrawing substituents are C₂-C₂₀ acyl group, C₂-C₂₀alkyloxycarbonyl group, nitro group, cyano group, C₁-C₂₀ alkylsulfonylgroup, C₆-C₂₀ arylsulfonyl group, C₁-C₂₀ carbamoyl group, and C₁-C₂₀halogenated alkyl group. Particularly preferred among theseelectron-withdrawing substituents are cyano group, C₁-C₂₀ alkylsulfonylgroup, and C₆-C₂₀ arylsulfonyl group. Cyano group is most desirable.

Z² represents a hydrogen atom or a substituent such as aliphatic group,aromatic group and heterocyclic group. Z² is preferably an aliphaticgroup, more preferably a C₁-C₆ alkyl group.

Q represents a hydrogen atom or a substituent such as aliphatic group,aromatic group and heterocyclic group. Q is preferably a group formed bya group of non-metallic atoms required to form a 5- to 8-membered ring.The aforementioned 5- to 8-membered ring may be substituted, may be asaturated ring or may have an unsaturated bond. Particularly preferredamong these 5- to 8-membered rings are aromatic group and heterocyclicgroup. Preferred examples of the non-metallic atom include nitrogenatom, oxygen atom, sulfur atom, and carbon atom. Specific examples ofthese cyclic structures include benzene ring, cyclopentane ring,cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclohexene ring,pyridine ring, pyrimidine ring, pyrazine ring, pyridazine ring, triazinering, imidazole ring, benzoimidazole ring, oxazole ring, benzoxazolering, thiazole ring, benzothiazole ring, oxane ring, sulfolane ring, andthiane ring.

The hydrogen atoms in the substituents described with reference to thegeneral formula (M-I) may be substituted. Examples of the substituentson these substituents include substituents listed with reference to thegeneral formula (M-I), and ionic hydrophilic groups exemplified withreference to G, R¹ and R².

The Hammett's substituent constant σp as used herein will be furtherdescribed hereinafter. Hammett's rule is an empirical rule which L. P.Hammett proposed in 1935 to quantitatively discuss the effect ofsubstituents on the reaction or equilibrium of benzene derivatives. Thevalidity of this empirical rule has been widely accepted today.Substituent constants required in Hammett's rule are up value and σmvalue. These values are found in many general literatures. For thedetails of these values, reference can be made to J. A. Dean, “Lange'sHandbook of Chemistry”, 12th ed., 1979 (McGraw-Hill), and “Kagaku noRyoiki (Region of Chemistry)”, extra edition, No. 122, pp. 96-103, 1979(Nankodo). In the invention, these substituents are defined or describedby Hammett's substituent constant up. However, this doesn't mean thatthe known values found in the aforementioned literatures are not limitedto certain substituents. It goes without saying that even if the valuesare unknown in literatures, they contain substituents which may fallwithin the defined range when measured according to Hammett's rule. Thecompounds of the general formula (Ia) of the invention contain thosewhich are not benzene derivatives. As a measure for indicating theelectron effect of substituents there is used σp value regardless ofsubstitution position. In the invention, op value is used in this sense.

Examples of the electron-withdrawing group having a Hammett'ssubstituent constant up of not smaller than 0.60 include cyano group,nitro group, and alkylsulfonyl group (e.g., methylsulfonyl, arylsulfonyl(e.g., phenylsulfonyl group)).

Examples of the electron-withdrawing group having a Hammett'ssubstituent constant op of not smaller than 0.45 include acyl groups(e.g., acetyl group), alkoxycarbonyl groups (e.g., dodecyloxycarbonylgroup), aryloxycarbonyl groups (e.g., m-chlorophenoxycarbonyl),alkylsulfinyl groups (e.g., n-propylsulfinyl), arylsulfinyl groups(e.g., phenylsulfinyl), sulfamoyl groups (e.g., N-ethylsulfamoyl,N,N-dimethylsulfamoyl), and halogenated alkyl groups (e.g.,trifluoromethyl), in addition to the aforementioned groups.

Examples of the electron-withdrawing group having a Hammett'ssubstituent constant σp of not smaller than 0.30 include acyloxy groups(e.g., acetoxy group), carbamoyl groups (e.g., N-ethylcarbamoyl groups,N,N-dibutylcarbamoyl group), halogenated alkoxy groups (e.g.,trifluoromethyloxy group), halogenated aryloxy groups (e.g.,pentafluorophenyloxy group), sulfonyloxy groups (e.g., methylsulfonyloxygroup), halogenated alkylthio groups (e.g., difluoromethylthio group),aryl groups substituted by two or more electron-withdrawing groupshaving a σp value of not smaller than 0.15 (e.g., 2,4-dinitrophenylgroup, pentafluorophenyl group), and heterocyclic groups (e.g.,2-benzooxazolyl group, 2-benzothiazolyl group,1-phenyl-2-benzoimidazolyl group), in addition to the aforementionedgroups.

Specific examples of the electron-withdrawing group having a up value ofnot smaller than 0.20 include halogen atoms, in addition to theaforementioned groups.

Referring to a particularly preferred combination of azo dyesrepresented by the general formula (M-I), R⁵ and R⁶ each are preferablya hydrogen atom, alkyl group, aryl group, heterocyclic group, sulfonylgroup or acyl group, more preferably hydrogen atom, aryl group,heterocyclic group or sulfonyl group, most preferably hydrogen atom,aryl group or heterocyclic group, with the proviso that R⁵ and R⁶ arenot a hydrogen atom at the same time.

G¹ is preferably a hydrogen atom, halogen atom, alkyl group, hydroxylgroup, amino group or acylamino group, more preferably hydrogen atom,halogen atom, amino group or acylamino group, most preferably hydrogenatom, amino group or acylamino group.

A¹ is preferably a pyrazole ring, imidazole ring, isothiazole ring,thiadiazole ring or benzothiazole ring, more preferably pyrazole ring orisothiazole ring, most preferably pyrazole ring.

B¹ and B² are ═CR¹— and —CR²═, respectively, in which R¹ and R² each arepreferably a hydrogen atom, alkyl group, halogen atom, cyano group,carbamoyl group, carboxyl group, hydroxyl group, alkoxy group oralkoxycarbonyl group, more preferably hydrogen atom, alkyl group,carboxyl group, cyano group or carbamoyl group.

Referring to a preferred combination of substituents on the compoundrepresented by the general formula (M-I), at least one of the varioussubstituents is preferably a compound which is a preferred group asmentioned above. More preferably, more of the various substituents arecompounds which are preferred groups as mentioned above. Mostpreferably, all the various substituents are compounds which arepreferred groups as mentioned above.

Specific examples of the compound (azo dye) represented by the generalformula (M−1) will be given below, but the azo dye to be used herein isnot limited thereto. TABLE 1

R₁ R₂ R₃ a-1

a-2

a-3

a-4

a-5

TABLE 2

R₁ R₂ R₃ a-6

a-7

a-8

a-9

C₈H₁₇(t) a-10

TABLE 3

R₁ R₂ R₃ R₄ a-11

a-12

a-13

a-14

a-15

a-16

a-17

TABLE 4

R₁ R₂ R₃ R₄ a-18

a-19

—SO₂CH₃

a-20

—COCH₃ C₈H₁₇(t) C₈H₁₇(t) a-21

—SO₂CH₃

C₈H₁₇(t) a-22

H

a-23

H

a-24

H

a-25

TABLE 5

R₁ R₂ R₃ R₄ a-26

a-27

a-28

a-29

a-30

C₈H₁₇(t) a-31

TABLE 6

R₁ R₂ R₃ R₄ a-32

a-33

a-34

a-35

TABLE 7

R₁ R₂ R₃ R₄ a-36

a-37

a-38

a-39

a-40

TABLE B

R₁ R₂ R₃ R₄ R₅ R₆ R₇ R₈ a-41

CN

H CONH₂ SO₂CH₃

a-42

Br

COOEt H

C₈H₁₇(t) COCH₃ a-43

SO₂CH₃

CONH₂ H

a-44

CN

H H

SO₂CH₃ a-45

Br

H CONH₂

a-46

CN

CH₃ H

TABLE 9

R₁ R₂ R₃ R₄ R₅ R₆ b-1 CH₃ CH₃ CN H

b-2 CH₃ CH₃ CN H

b-3 CH₃ CH₃ CONH₂ H

b-4 CH₃ CH₃ H H

b-5 CH₃ H CN H

TABLE 10

R₁ R₂ R₃ R₄ R₅ R₆ b-6 CH₃ CH₃ H

b-7 CH₃ CH₃ H

b-8 CH₃ H H SO₂CH₃

TABLE 11

R₁ R₂ R₃ R₄ R₅ R₆ c-1 —SCH₃ CH₃ CN H C₈H₁₇(t)

c-2

H CONH₂ H

c-3

CH₃ H

c-4 —CH₃ CH₃ H

c-5

H H

C₈H₁₇(t)

TABLE 12

R₁ R₂ R₃ R₄ R₅ R₆ d-1 Me CH₃ CN H

d-2 Me CH₃ CN H

d-3 Me H H

d-4 Ph CH₃ CONH₂ H

d-5 Ph CH₃ H

TABLE 13

R₁ R₂ R₃ R₄ R₅ R₆ e-1 5-Cl CH₃ CONH₂ H O₈H₁₇(t) C₈H₁₇(t) e-2 5,6-diCl HH

e-3 5,6-diCl CH₃ H

COCH₃ e-4 5-CH₂ H CN H

e-5 5-NO₂ CH₃ H SO₂CH₃

f-1

f-2

The preferred magenta ink composition comprises at least one of the azodyes (M-1) dissolved and/or dispersed in an aqueous medium preferably inan amount of from 0.2% to 20% by weight, more preferably from 0.5% to15% by weight.

The azo dye (M−1) to be used in the invention is substantiallywater-soluble. The term “substantially water-soluble” as used herein ismeant to indicate that the azo dye is dissolved in 20° C. water in anamount of not smaller than 2% by weight.

The magenta ink composition may comprise other magenta dyestuffsincorporated therein in combination with the azo dye (M−1).

Examples of magenta dyestuffs include aryl or heterylazo dyestuffs(other than the azo dye of the general formula (M-I) of the invention)having phenols, naphthols or anilines as coupling components, azomethinedyestuffs having pyrazolones or pyrazolotriazoles as couplingcomponents, methine dyestuffs such as arylidene dyestuff, styryldyestuff, melocyanine dyestuff and oxonol dyestuff, carbonium dyestuffssuch as diphenylmethane dyestuff, triphenylmethane dyestuff and xanthenedyestuff, quinone-based dyestuffs such as naphthoquinone, anthraquinoneand anthrapyridone, and condensed polycyclic dyestuffs such as dioxazinedyestuff. These dyestuffs may assumes magenta only when chromophore ispartly, dissociated. In this case, the counter cation may be aninorganic cation such as alkaline metal ion and ammonium ion or anorganic cation such as pyridinium ion and quaternary ammonium salt ionor may be contained in a polymer cation as a partial structure.

The coloring agent to be used as a cyan ink in the invention preferablycomprises an electron-withdrawing group incorporated in itsphthalocyanine skeleton to have an oxidation potential of higher than1.0 V (vs SCE) in order to deteriorate the reactivity with an oxidizinggas such as ozone gas. The oxidation potential of the coloring agent ispreferably higher, more preferably higher than 1.1 V (vs SCE), mostpreferably higher than 1.2 V (vs SCE).

The oxidation potential value (Eox) can be easily measured by thoseskilled in the art. For the details of the method for measuring theoxidation potential, reference can be made to P. Delahay, “NewInstrumental Methods in Electrochemistry”, Interscicence Publishers,1954, A. J. Bard, “Electrochemical Methods”, John Wiley & Sons, 1980,and Akiya Fujishima, “Denki Kagaku Sokuteiho (Electrochemical MeasuringMethod)”, Gihodo Shuppansha, 1984.

In some detail, the measurement of oxidation potential is carried out bydissolving the test specimen in a solvent containing a supportingelectrolyte such as sodium perchlorate and tetrapropylammoniumperchlorate in a concentration of from 1×10⁻⁴ to 1×10⁻⁶ mol/l, and thenmeasuring the test solution for oxidation potential with respect to SCE(saturated calomel electrode) using cyclic voltammetry or DCpolarography. This value may deviate by scores of millivolts due to theeffect of difference in potential between solutions or resistivity oftest solution. However, the incorporation of a standard specimen (e.g.,hydroquinone) makes it possible to assure the reproducibility ofpotential.

In order to unequivocally define potential, the potential (vs SCE)measured in dimethylformamide containing 0.1 mol dm⁻³ oftetrapropylammonium perchlorate as a supporting electrolyte(concentration of dye: 0.001 mol dm⁻³) using DC polarography is definedas oxidation potential of dye.

The value of Eox (oxidation potential) indicates the transferability ofelectrons from the specimen to the electrode. The greater this value is(the higher the oxidation potential is) the more difficultly can betransferred electrons from the specimen to the electrode, i.e., the moredifficultly can be oxidized the specimen. With regard to the structureof the compound, the incorporation of electron-withdrawing group causesthe oxidation potential to be higher while the incorporation ofelectron-donative group causes the oxidation potential to be lower. Inthe invention, in order to deteriorate the reactivity with ozone, whichis an electron-withdrawing agent, it is preferred that anelectron-withdrawing group be incorporated in the phthalocyanineskeleton to cause the oxidation potential to be higher. The use ofHammett's substituent constant σp, which is a measure of the electronwithdrawing properties or electron providing properties of substituents,makes it possible to tell that the incorporation of, substituents havinga great σp value such as sulfinyl group, sulfonyl group and sulfamoylgroup makes it possible to cause the oxidation potential to be higher.

In the invention, the phthalocyanine dye represented by the generalformula (C-I) is particularly preferred.

The compound of the general formula (C-I) to be used in the inventionwill be further described hereinafter,

In the general formula (C-I), X₁, X₂, X₃ and X₄ each independentlyrepresent —SO-Z, —SO₂-Z, —SO₂NR₁R₂, sulfo group, —CONR₁R₂ or —CO₂R₁.Preferred among these substituents are —SO-Z, —SO₂-Z, —SO₂NR₁R₂ and—CONR₁R₂. Particularly preferred among these substituents are —SO₂-Z and—SO₂NR₁R₂. Most desirable among these substituents is —SO₂-Z. In thecase where any of a₁ to a₄ and b₁ to b₄, which represent the number ofsubstituents on X₁ to X₁ and Y₁ to Y₄, represents a number of notsmaller than 2, the plurality of X₁'s to X₄'s may be the same ordifferent and each independently represent any of the aforementionedgroups. Alternatively, X₁, X₂, X₃ and X₄ may be the same substituent.Alternatively, X₁, X₂, X₃ and X₄ each may be —SO₂-Z in which Z differsamong X₁, X₂, X₃ and X₄. Thus, X₁, X₂, X₃ and X₄ each may be asubstituent of the same kind but partially different. Alternatively, X₁,X₂, X₃ and X₄ may be different substituents, e.g., —SO₂-Z, —SO₂NR₁R₂.

Z each independently represents a substituted or unsubstituted alkylgroup, substituted or unsubstituted cycloalkyl group, substituted orunsubstituted alkenyl group, substituted or unsubstituted aralkyl group,substituted or unsubstituted aryl group and 0 substituted heterocyclicgroup. Preferred among these groups are substituted or unsubstitutedalkyl group, substituted or unsubstituted aryl group and substituted orunsubstituted heterocyclic group. Particularly preferred among thesegroups are substituted alkyl group, substituted aryl group andsubstituted heterocyclic group.

R₁ and R₂ each independently represent a hydrogen atom, substituted orunsubstituted alkyl group, substituted or unsubstituted cycloalkylgroup, substituted or unsubstituted alkenyl group, substituted orunsubstituted aralkyl group, substituted or unsubstituted aryl group orsubstituted or unsubstituted heterocyclic group. Preferred among thesegroups are hydrogen atom, substituted or unsubstituted alkyl group,substituted or unsubstituted aryl group or substituted or unsubstitutedheterocyclic group. Particularly preferred among these groups arehydrogen atom, substituted alkyl group, substituted aryl group orsubstituted heterocyclic group. However, it is not preferred that R₁ andR₂ are a hydrogen atom at the same time.

The substituted or unsubstituted alkyl group represented by R₁, R₂ or Zis preferably a C₁-C₃₀ alkyl group. Particularly from the reason ofenhancement of dye solubility or ink stability, the alkyl group ispreferably branched. It is particularly preferred that the alkyl grouphave a symmetric carbons (used in racemate form). Examples of thesubstituents on the alkyl group include those listed with reference tothe case where Z, R₁, R₂, Y₁, Y₂, Y₃ and Y₄ are able to have furthersubstituents as described later. Particularly preferred among thesesubstituents are hydroxyl group, ether group, ester group, cyano group,amide group and sulfonamide group because they enhance the associationof dyes and hence the fastness thereof. Alternatively, the alkyl groupmay have a halogen atom or ionic hydrophilic group. The number of carbonatoms in the alkyl group doesn't include that of carbon atoms in thesubstituents. This can apply to other groups.

The substituted or unsubstituted cycloalkyl group represented by R₁, R₂or Z is preferably a C₅-C₃₀ cycloalkyl group. Particularly from thereason of enhancement of dye solubility or ink stability, it isparticularly preferred that the cycloalkyl group have asymmetric carbons(used in racemate form). Examples of the substituents on the cycloalkylgroup include those listed with reference to the case where Z, R₁, R₂,Y₁, Y₂, Y₃ and Y₄ are able to have further substituents as describedlater. Particularly preferred among these substituents are hydroxylgroup, ether group, ester group, cyano group, amide group andsulfonamide group because they enhance the association of dyes and hencethe fastness thereof. Alternatively, the cycloalkyl group may have ahalogen atom or ionic hydrophilic group.

The substituted or unsubstituted alkenyl group represented by R₁, R₂ orZ is preferably a C₂-C₃₀ alkenyl group. Particularly from the reason ofenhancement of dye solubility or ink stability, the alkenyl group ispreferably branched. It is particularly preferred that the alkenyl grouphave asymmetric carbons (used in racemate form). Examples of thesubstituents on the alkenyl group include those listed with reference tothe case where Z, R₁, R₂, Y₁, Y₂, Y₃ and Y₄ are able to have furthersubstituents as described later.

fastness thereof. Examples of the electron-withdrawing group includethose having a positive Hammett's substituent constant op. Preferredexamples of the electron-withdrawing group include halogen atom,heterocyclic group, cyano group, carboxyl group, acylamino group,sulfonamide group, sulfamoyl group, carbamoyl group, sulfonyl group,imide group, acyl group, sulfo group, and quaternary ammonium group.Particularly preferred among these electron-withdrawing groups are cyanogroup, carboxyl group, sulfamoyl group, carbamoyl group, sulfonyl group,imide group, acyl group, sulfo group, and quaternary ammonium group.

The heterocyclic group represented by R₁, R₂ or Z is preferably a 5- or6-membered heterocyclic group which may be further condensed. Theheterocyclic group may be an aromatic heterocyclic group or non-aromaticheterocyclic group. The heterocyclic group represented by R₁, R₂ or Zwill be exemplified in the form of heterocyclic ring with itssubstitution position omitted. However, the substitution position is notlimited. For example, pyridine may have substituents on the 2-, 3-or4-position. Examples of the heterocyclic ring include pyridine,pyrazine, pyrimidine, pyridazine, triazine, quinoline, isoquinoline,quinazoline, cinnoline, phthaladine, quinoxaline, pyrrole, indole,furane, benzofurane, thiophene, benzothiophene, pyrazole, imidazole,benzimidazole, triazole, oxazole, benzoxaole, thiazole, benzothiazole,isothiazole, benzisothiazole, thiadiazole, isooxazole, benzisooxazole,pyrrolidine, piperidine, piperazine, imidazolidine, and thiazoline. Inparticular, aromatic heterocyclic groups are preferred. Preferredexamples of the aromatic heterocyclic groups include pyridine, pyrazine,pyrimidine, pyridazine, triazine, pyrazole, imidazole, benzimidazole,triazole, thiazole, benzothiazole, isothiazole, benzisothiazole, andthiadiazole. These aromatic heterocyclic groups may have substituents.Examples of the substituents on the aromatic heterocyclic group includethose listed with reference to the case where Z, R₁, R₂, Y₁, Y₂, Y₃ andY₄ are able to have further substituents as described later. Preferredexamples of the substituents include those listed with reference to theaforementioned aryl group. Even more desirable examples of thesubstituents include those listed with reference to the aforementionedaryl group.

Y₁, Y₂, Y₃ and Y₄ each independently represent a hydrogen atom, halogenatom, alkyl group, cycloalkyl group, alkenyl group, aralkyl group, arylgroup, heterocyclic group, cyano group, hydroxyl group, nitro group,amino group, alkylamino group, alkoxy group, aryloxy group, acylaminogroup, arylamino group, ureide group, sulfamoyl group, alkylthio group,arylthio group, alkoxycarbonylamino group, sulfonamide group, carbamoylgroup, sulfamoyl group, sulfonyl group, alkoxycarbonyl group,heterocyclic oxy group, azo group, acyloxy group, carbamoyloxy group,silyloxy group, aryloxycarbonyl group, aryloxycarbonylamino group, imidegroup, heterocyclic thio group, phosphoryl group, acyl group, carboxylgroup or sulfo group which may further have substituents.

Preferred among these groups are hydrogen atom, halogen atom, alkylgroup, aryl group, cyano group, alkoxy group, amide group, ureide group,sulfonamide group, carbamoyl group, sulfamoyl group, alkoxycarbonylgroup, carboxyl group and sulfo group. Particularly preferred amongthese groups are hydrogen atom, halogen atom, cyano group, carboxylgroup and sulfo group. Most desirable among these groups is hydrogenatom.

In the case where Z, R₁, R₂, Y₁, Y₂, Y₃ and Y₄ may further havesubstituents, they may further have the following substituents.

Examples of the substituents on Z, R₁, R₂, Y₁, Y₂, Y₃ and Y₄ includeC₁-C₁₂ straight-chain or branched alkyl group, C₇-C₁₉ straight-chain orbranched aralkyl group, C₂-C₁₂ straight-chain or branched alkenyl group,C₂-C₁₂ straight-chain or branched alkinyl group, C₃-C₁₂ straight-chainor branched cycloalkyl group, C₃-C₁₂ straight-chain or branchedcycloalkenyl group (These groups each preferably have branches for thereason of dye solubility or ink stability. It is particularly preferredthat these groups have asymmetric carbons. Specific examples of thesegroups include methyl group, ethyl group, propyl group, isopropyl group,sec-butyl group, t-butyl group, 2-ethylhexyl group,2-methylsulfonylethyl group, 3-phenoxypropyl group, trifluoromethylgroup, and cyclopentyl group), halogen atom (e.g., chlorine atom,bromine atom), aryl group (e.g., phenyl group, 4-t-butylphenyl group,2,4-di-t-amylphenyl group), heterocyclic group (e.g., imidazolyl group,pyrazolyl group, triazolyl group, 2-furyl group, 2-chenyl group,2-pyrimidinyl group, 2-benzothiazolyl group), cyano group, hydroxylgroup, nitro group, carboxy group, amino group, alkyloxy group (e.g.,methoxy group, ethoxy group, 2-methoxyethoxy group,2-methanesulfohykethoxy group), aryloxy group (e.g., phenoxy group,2-methylphenoxy group, 4-t-butylphenoxy group, 3-nitrophenoxy group,3-t-butyloxycarbamoylphenoxy group, 3-methoxycarbamoyl group), acylaminogroup (e.g., acetamide group, benzamide group,4-(3-t-butyl-4-hydroxyphenoxy)butanamide group), alkylamino group (e.g.,methylamino group, butylamino group, diethylamino group,methylbutylamino group), anilino group (e.g., phenylamino group,2-chloroanilino group), ureide group (e.g., phenylureide group,methylureide group, N,N-dibutylureide group), sulfamoylamino group(e.g., N,N-dipropylsulfamoylamino group), alkylthio group (e.g.,methylthio group, octylthio group, 2-phenoxyethylthio group), arylthiogroup (e.g., phenylthio group, 2-butoxy-5-t-octylphenylthio group,2-carboxyphenylthio group), alkyloxycarbonylamino group (e.g.,methoxycarbonylamino group), sulfonamide group (e.g., methanesulfonamidegroup, benzenesulfonamide group, p-toluenesulfonamide group), carbamoylgroup (e.g., N-ethylcarbamoyl group, N,N-dibutylcarbamoyl group),sulfamoyl group (e.g., N-ethylsulfamoyl group, N,N-dipropylsulfamoylgroup, N-phenylsulfamoyl group), sulfonyl group (e.g., methanesulfonylgroup, octanesulfonyl group, benzenesulfonyl group, toluenesulfonylgroup), alkyloxycarbonyl group (e.g., methoxycarbonyl group,butyloxycarbonyl group), heterocyclic oxy group (e.g.,1-phenyltetrazole-5-oxy group, 2-tetrahydropyranyloxy group), azo group(e.g., phenylazo group, 4-methoxyphenylazo group,4-pivaloylaminophenylazo group, 2-hydroxy-4-propanoylphenylazo group),acyloxy group (e.g., acetoxy group), carbamoyloxy group (e.g.,N-methylcarbamoyloxy group, N-phenylcarbamoyloxy group), silyloxy group(e.g., trimethylsilyloxy group, dibutylmethylsilyloxy group),aryloxycarbonylamino group (e.g., phenoxycarbonylamino group) imidegroup (e.g., N-succinimide group, N-phthalimide group), heterocyclicthio group (e.g., 2-benzothiazolylthio group,2,4-d]-phenoxy-1,3,5-triazole-6-thio group, 2-pyridylthio group),sulfinyl group (e.g., 3-phenoxypropylsulfinyl group), phosphonyl group(e.g., phenoxyphosphonyl group, octyloxyphosphonyl group,phenylphosphonyl group), aryloxycarbonyl group (e.g., phenoxycarbonylgroup), acyl group (e.g., acetyl group, 3-phenylpropanoyl group, benzoylgroup), and ionic hydrophilic group (e.g., carboxyl group, sulfo group,phosphono group, quaternary ammonium group).

The phthalocyanine dye represented by the general formula (C-I), if itis water-soluble, preferably has an ionic hydrophilic group. Examples ofthe ionic hydrophilic group include sulfo group, carboxyl group,phosphono group, and quaternary ammonium group. Preferred among theseionic hydrophilic groups are carboxyl group, phosphono group, and sulfogroup. Particularly preferred among these ionic hydrophilic groups arecarboxyl group and sulfo group. The carboxyl group, phosphono group andsulfo group may be used in the form of salt. Examples of the counter ionforming the salt include ammonium ion, alkaline metal ion (e.g., lithiumion, sodium ion, potassium ion), and organic cation (e.g.,tetramethylammonium ion, tetramethylguanidium ion, tetraethylphosphoniumion). Preferred among these counter ions are alkaline metal ions.Particularly preferred among these counter ions is lithium ion becauseit enhances the dye solubility and hence the ink stability.

The number of ionic hydrophilic groups is preferably at least 2 permolecule of phthalocyanine-based dye. It is particularly preferred thatthere be contained at least two sulfo groups and/or carboxyl groups inthe phthalocyanine-based dye.

The suffixes a₁ to a₄ and b₁ to b₄ represent the number of thesubstituents X₁ to X; and Y₁ to Y₄, respectively. The suffixes a₁ to a₄each independently represent an integer of from 0 to 4, with the provisothat the suffixes a₁ to a₄ are not 0 at the same time. The suffixes b₁to b₄ each independently represent an integer of from 0 to 4. When anyof a₁ to ad and b₁ to b₄ is an integer of not smaller than 2, there area plurality of any of X₁'s to X₄'s and Y₁'s to Y₄'s. They may be thesame or different.

The suffixes a₁ and b₁ satisfy the equation a₁+b₁=4. In a particularlypreferred combination, a₁ represents 1 or 2 while b₁ represents 3 or 2.In the best combination, a₁ represents 1 while b, represents 3.

The combinations a₂ and b₂, a₃ and b₃, and a₄ and b₄ are similar to thecombination of a₁ and b₁. Preferred examples of the combinations a₂ andb₂, a₃ and b₃, and a₄ and b₄ are also similar to that of the combinationof a₁ and b₁.

M represents a hydrogen atom, metal element or oxide, hydroxide orhalide thereof.

Preferred examples of M other than hydrogen atom include metal elementssuch as Li, Na, K, Mg, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Pe, Co, Ni, Ru,Rh, Pd, Os, Ir, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Si, Ge, Sn, Pb,Sb and Bi. Preferred examples of metal oxide include VO, and GeO.Preferred examples of metal hydroxide include Si(OH)₂, Cr (OH)₂, andSn(OH)₂. Examples of metal halide include AlCl, SiCl₂, VCl, VCl₂, VOCl,FeCl, GaCl, and ZrCl. Preferred among these metal elements are Cu, Ni,Zn, and Al. Most desirable among these metal elements is Cu.

Pc (phthalocyanine ring) may form a diameter (e.g., Pc-M-L-M-Pc) ortrimer with L (divalent connecting group) interposed therebetween. Inthis case, M's may be the same or different.

Preferred groups of the divalent connecting group represented by Linclude oxy group —O—, thio group —S—, carbonyl group —Co—, sulfonylgroup —SO₂—, imino group —NH—, methylene group —CH2—, and group formedby combining these groups.

Referring to preferred combination of substituents on the compoundrepresented by the general formula (C-I), the compound of the generalformula (I-b) preferably has various substituents at least one of whichis one of the preferred groups listed above. More preferably, more ofthe various substituents are the preferred groups listed above. Mostpreferably, all of the various substituents are the preferred groupslisted above.

Preferred among the phthalocyanine dyes represented by the generalformula (C-I) is a phthalocyanine dye having the structure representedby the general formula (C-II). The phthalocyanine dye represented by thegeneral formula (C-II) which is particularly preferred in the inventionwill be described in detail hereinafter,

In the general formula (C-II), X₁₁ to X₁₄ and Y₁₁ to Y₁₈ and theirpreferred examples are as defined in the general formula (C-I). M andits preferred examples are as defined in the general formula (C-I).

In the general formula (C-II), a₁₁ to a₁₄ each independently representan integer of from 1 or 2. Preferably, the sum of a₁₁ to a₁₄ is from notsmaller than 4 to not greater than 6. It is particularly preferred thata₁₁ to a₁₄ be 1 at the same time.

X₁₁, X₁₂, X₁₃ and X₁₄ may be the same substituent. Alternatively, X₁₁,X₁₂, X₁₃ and X₁₄ each may be —SO₂-Z in which Z differs among X₁, X₂, X₃and X₄. Thus, X₁₁, X₁₂, X₁₃ and X₁₄ each may be a substituent of thesame kind but partially different. Alternatively, X₁₁, X₁₂, X₁₃ and X₁₄may be different substituents, e.g., —SO-Z, —SO₂NR₁R.

Particularly preferred examples of the combination of substituents amongthe phthalocyanine dyes represented by the general formula (C-II) willbe given below.

Preferably, X₁₁ to X₁₄ each independently represent —SO-Z, —SO₂-Z,—SO₂NR₁R₂ or —CONR₁R₂, particularly —SO₂-Z or —SO₂NR₁R₂, most preferably—SO₂-Z.

Z each independently represents a substituted or unsubstituted alkylgroup, substituted or unsubstituted aryl group or substituted orunsubstituted heterocyclic group. Most desirable among these groups aresubstituted alkyl group, substituted aryl and substituted heterocyclicgroup. Particularly for the reason of enhancement of dye solubility orink stability, it is preferred that the substituents have asymmetriccarbons (used in racemate form). Further, for the reason of enhancementof association and hence fastness, it is preferred that the substituentshave a hydroxyl group, ether group, ester group, cyano group, amidegroup or sulfonamide group incorporated therein.

R₁ and R₂ each independently represent a hydrogen atom, substituted orunsubstituted alkyl group, substituted or unsubstituted aryl group orsubstituted or unsubstituted heterocyclic group, particularly a hydrogenatom, substituted alkyl group, substituted aryl group or substitutedheterocyclic group. However, it is not preferred that R₁ and R₂ each area hydrogen atom at the same time. Particularly for the reason ofenhancement of dye solubility or ink stability, it is preferred that thesubstituents have asymmetric carbons (used in racemate form). Further,for the reason of enhancement of association and hence fastness, it ispreferred that the substituents have a hydroxyl group, ether group,ester group, cyano group, amide group or sulfonamide group incorporatedtherein.

Y₁₁ to Y₁₈ each independently represent a hydrogen atom, halogen atom,alkyl group, aryl group, cyano group, alkoxy group, amide group, ureidegroup, sulfonamide group, carbamoyl group, sulfamoyl group,alkoxycarbonyl group, carboxyl group or sulfo group, particularlyhydrogen atom, halogen atom, cyano group, carboxyl group or sulfo group,most preferably hydrogen atom.

The suffixes a₁₁ to a₁₄ each independently represent 1 or 2. It isparticularly preferred that a₁₁ to a₁₄ each be 1 at the same time.

M represents a hydrogen atom, metal element or oxide, hydroxide orhalide thereof, particularly Cu, Ni, Zn or Al, most preferably Cu.

The phthalocyanine dye represented by the general formula (C-II), if itis water-soluble, preferably has an ionic hydrophilic group. Examples ofthe ionic hydrophilic group include sulfo group, carboxyl group,phosphono group, and quaternary ammonium group. Preferred among theseionic hydrophilic groups are carboxyl group, phosphono group, and sulfogroup. Particularly preferred among these ionic hydrophilic groups arecarboxyl group and sulfo group. The carboxyl group, phosphono group andsulfo group may be used in the form of salt. Examples of the counter ionforming the salt include ammonium ion, alkaline metal ion (e.g., lithiumion, sodium ion, potassium ion), and organic cation (e.g.,tetramethylammonium ion, tetramethylguanidium ion,tetramethylphosphonium ion). Preferred among these counter ions arealkaline metal ions. Particularly preferred among these counter ions islithium ion because it enhances the dye solubility and hence the inkstability.

The number of ionic hydrophilic groups is preferably at least 2 permolecule of phthalocyanine-based dye. It is particularly preferred thatthere be contained at least two sulfo groups and/or carboxyl groups inthe phthalocyanine-based dye.

Referring to preferred combination of substituents on the compoundrepresented by the general formula (C-II), the compound of the generalformula (C-II) preferably has various substituents at least one of whichis one of the preferred groups listed above. More preferably, more ofthe various substituents are the preferred groups listed above. Mostpreferably, all of the various substituents are the preferred groupslisted above.

Referring to the chemical structure of the phthalocyanine dye accordingto the invention, it is preferred that at least one electron-withdrawinggroup such as sulfinyl group, sulfonyl group and sulfamoyl group beincorporated in each of four benzene rings in the phthalocyanine suchthat op value of the substituents in the entire phthalocyanine skeletontotals not smaller than 1.6.

The Hammett's substituent constant op as used herein will be somewhatdescribed hereinafter. Hammett's rule is an empirical rule which L. P.Hammett proposed in 1935 to quantitatively discuss the effect ofsubstituents on the reaction or equilibrium of benzene derivatives. Thevalidity of this empirical rule has been widely accepted today.Substituent constants required in Hammett's rule are up value and amvalue. These values are found in many general literatures. For thedetails of these values, reference can be made to J. A. Dean, “Lange'sHandbook of Chemistry”, 12th ed., 1979 (Mc Graw-Hill), and “Kagaku noRyoiki (Region of Chemistry)”, extra edition, No. 122, pp. 96-103, 1979(Nankodo).

The phthalocyanine derivative represented by the general formula (C-I)is normally a mixture of analogues which are unavoidably different inintroduction sites of substituents Xn (n=1 to 4) and Ym (m=1 to 4) andintroduced number of these substituents by synthesis method.Accordingly, the general formula of the phthalocyanine dye is mostly astatistically averaged representation of these analogous mixtures. Inthe invention, it was found that the classification of these analogousmixtures into the following three classes gives a specific mixture whichis particularly preferred. In other words, mixtures ofphthalocyanine-based dye analogues represented by the general formulae(C-I) and (C-II) are classified into the following classes fordefinition.

(1) β-position substitution type: Phthalocyanine dye having a specificsubstituent on 2- and/or 3-position, 6- and/or 7-position, 10- and/or11-position, or 14- and/or 15-position

(2) α-position substitution type: Phthalocyanine dye having a specificsubstituent on 1- and/or 4-position, 5- and/or 8-position, 9- and/or12-position, or 13- and/or 16-position

(3) α,β-position mixed substitution type: Phthalocyanine dye having aspecific substituent irregularly on 1- to 16-position

In the specification, in order to describe phthalocyanine dyederivatives having different structures (particularly differentsubstitution positions), the aforementioned β-position substitutiontype, α-position substitution type and α,β-position mixed substitutiontype are used.

The phthalocyanine derivative to be used in the invention can besynthesized by, e.g., methods described or cited in Shirai andKobayashi, “Phthalocyanine—Chemistry and Function—”, IPC Co., Ltd., pp.1 to 62, C. C. Leznoff-A.B.P. Lever, “Phthalocyanines—Properties andApplications”, VCH, pp. 1-54, etc. or analogous methods in combination.

The phthalocyanine compound represented by the general formula (C-I) tobe used in the invention can be synthesized by, e.g., sulfonationreaction, sulfonylchloration reaction and amidation reaction ofunsubstituted phthalocyanine compound as disclosed in World Patents00/17275, 00/08103, 00/08101 and 98/41853 and JP-A-10-36471. In thiscase, since sulfonation can occur on any position of the phthalocyaninenucleus, it is difficult to control the sulfonated number ofsubstituents. Accordingly, when sulfo groups are incorporated under sucha reaction condition, the position and number of sulfo groupsincorporated in the reaction product cannot be predetermined,unavoidably giving a mixture of products having different numbers ofsubstituents or substitution positions. Thus, since when this mixture isused as a starting material to synthesize the compound of the invention,a α,β-mixed substitution type mixture comprising some compounds havingdifferent numbers of substituents or substitution positions is obtainedas a compound suitable for ink set of the invention because the numberof heterocyclic group-substituted sulfamoyl groups or the substitutionposition cannot be predetermined.

As previously mentioned, when many electron-withdrawing groups such assulfamoyl group are incorporated in the phthalocyanine nucleus, thephthalocyanine dye is provided with a higher oxidation potential andhence an enhanced ozone fastness. When synthesized according to theaforementioned method, it is unavoidable that the reaction mixturecontains a phthalocyanine dye having a small number ofelectron-withdrawing groups incorporated therein, i.e., lower oxidationpotential. Accordingly, in order to enhance the ozone fastness of thephthalocyanine dye, a synthesis method capable of inhibiting theproduction of a compound having a lower oxidation potential ispreferably employed.

In the invention, the phthalocyanine compound represented by the generalformula (C-II) can be derived from a tetrasulfophthalocyanine compoundobtained by, e.g., reacting a phthalonitrile derivative (compound P)represented by the following general formula and/or a diiminoisoindolinederivative (compound Q) represented by the following general formulawith a metal compound represented by the general formula (III) orreacting a 4-sulfophthalocyanine derivative (compound R) represented bythe following general formula with a metal compound represented by thegeneral formula (III).

In these general formulae, Xp corresponds to X₁₁, X₁₂, X₁₃ or X₁₄ in thegeneral formula (C-II). Yq and Yq′ each correspond to Y₁₁, Y₁₂, Y₁₃,Y₁₄, Y₁₅, Y₁₆, Y₁₇ or Y₁₈ in the general formula (C-II). In the compoundR, M′ represents a cation.

Examples of the cation represented by M′ include alkaline metal ionssuch as Li, Na and K ions and organic cations such as triethylammoniumion and pyridinium ion.M-(Y)d  (III)wherein M is as defined in the general formula (C-I); Y represents amonovalent or divalent ligand such as halogen atom, acetate anion,acetyl acetonate and oxygen; and d represents an integer of from 1 to 4.

In other words, when synthesized according to the aforementioned method,desired substituents can be incorporated by a predetermined number. Inparticular, in order to introduce many electron-withdrawing groups tomake the oxidation potential higher as in the invention, theaforementioned synthesis method can be used because it is extremelyexcellent as compared with the aforementioned method for synthesis ofthe phthalocyanine compound of the general formula (C-I).

The phthalocyanine compound represented by the general formula (C-II)thus obtained is a mixture of compounds represented by the followinggeneral formulae (a)-1 to (a)-4 which are isomeric with the substitutionposition on Xp, i.e., β-position substitution type mixture.

In the foregoing synthesis method, when the same compound is used as Xp,a β-position substitution type phthalocyanine dye wherein X₁₁, X₁₂, X₁₃and X₁₄ are the same substituent can be obtained. On the contrary, whendifferent materials are used in combination as Xp, a dye havingsubstituents of the same kind but partially different or a dye havingdifferent substituents can be synthesized. Among the dyes of the generalformula (C-II), these dyes having different electron-withdrawingsubstituents are particularly desirable because they can adjust thesolubility and association of the dye, the age stability of the ink,etc.

In the invention, it was found very important for the enhancement offastness that any of these substitution types has an oxidation potentialof higher than 1.0 V (vs SCE). The degree of this effect could not beexpected from the related art. Although its mechanism is not known indetail, a tendency was given that β-position substitution type isobviously better than α,β-position mixed substitution type in hue, lightfastness, ozone fastness, etc.

Specific examples of the phthalocyanine dyes represented by the generalformulae (C-I) and (C-II) (exemplary compounds I-1 to I-12 and 101 to190) will be given below, the phthalocyanine dye to be used in theinvention is not limited thereto.

In the following tables, specific examples of various combinations of(X₁, X₂), (Y₁₁, Y₁₂), (Y₁₃, Y₁₄), (Y₁₅, Y₁₆), and (Y₁₇, Y₁₈) are eachindependently not in order. TABLE 14

No. M X₁ X₂ Y₁₁, Y₁₂ Y₁₃, Y₁₄ Y₁₅, Y₁₆ Y₁₇, Y₁₈ 101 Cu—SO₂—NH—CH₂—CH₂—SO₃Li —H —H, —H —H, —H —H, —H —H, —H 102 Cu

—H —Cl, —H —Cl, —H —Cl, —H —Cl, —H 103 Cu

—H —H, —H —H, —H —H, —H —H, —H 104 Cu

—H —H, —H —H, —H —H, —H —H, —H 105 Ni

—H —Cl, —H —Cl, —H —Cl, —H —Cl, —H 106 Cu—SO₂—NH—CH₂—CH₂—SO₂—NH—CH₂—COOHa —CN —H, —H —H, —H —H, —H —H, —H 107 Cu

—H —H, —H —H, —H —H, —H —H, —H 108 Cu —SO₂—CH₂—CH₂—CH₂—SO₃Li —H —H, —H—H, —H —H, —H —H, —H 109 Cu —SO₂—CH₂—CH₂—CH₂—SO₃K —H —H, —H —H, —H —H,—H —H, —H 110 Cu —SO₂—(CH₂)₃—CO₂K —H —H, —H —H, —H —H, —H —H, —H

TABLE 15

No. M X₁ X₂ Y₁₁, Y₁₂ Y₁₃, Y₁₄ Y₁₅, Y₁₆ Y₁₇, Y₁₈ 111 Cu

—H —H, —H —H, —H —H, —H —H, —H 112 Cu

—SO₃Li —H, —H —H, —H —H, —H —H, —H 113 Cu

—H —H, —H —H, —H —H, —H —H, —H 114 Cu

—SO₃Li —H, —H —H, —H —H, —H —H, —H 115 Cu

—H —H, —H —H, —H —H, —H —H, —H 116 Cu

—H —H, —H —H, —H —H, —H —H, —H 117 Cu

—H —H, —H —H, —H —H, —H —H, —H

TABLE 16

No. M X₁ X₂ Y₁₁, Y₁₂ Y₁₃, Y₁₄ Y₁₅, Y₁₆ Y₁₇, Y₁₈ 118 Cu

—H —H, —H —H, —H —H, —H —H, —H 119 Cu

—H —H, —H —H, —H —H, —H —H, —H 120 Cu

—H —H, —H —H, —H —H, —H —H, —H 121 Cu

—H —H, —H —H, —H —H, —H —H, —H 122 Cu

—H —H, —H —H, —H —H, —H —H, —H 123 Cu —SO₂NH—C₈H₁₇(t) —H —H, —H —H, —H—H, —H —H, —H 124 Cu

—H —H, —H —H, —H —H, —H —H, —H

TABLE 17

No. M X₁ X₂ Y₁₁, Y₁₂ Y₁₃, Y₁₄ Y₁₅, Y₁₆ Y₁₇, Y₁₈ 125 Cu

—H —H, —H —H, —H —H, —H —H, —H 126 Cu

—H —H, —H —H, —H —H, —H —H, —H 127 Cu

—H —H, —H —H, —H —H, —H —H, —H 128 Zn

—CN —H, —H —H, —H —H, —H —H, —H 129 Cu

—H —Cl, —H —Cl, —H —Cl, —H —Cl, —H 130 Cu

—H —H, —H —H, —H —H, —H —H, —H 131 Cu

—H —H, —H —H, —H —H, —H —H, —H

TABLE 18

No. M X₁ X₂ Y₁₁, Y₁₂ Y₁₃, Y₁₄ Y₁₅, Y₁₆ Y₁₇, Y₁₈ 132 Cu

—H —H, —H —H, —H —H, —H —H, —H 133 Cu

—H —H, —H —H, —H —H, —H —H, —H 134 Cu

—H —H, —H —H, —H —H, —H —H, —H 135 Cu

—H —H, —H —H, —H —H, —H —H, —H 136 Cu

—H —H, —H —H, —H —H, —H —H, —H

TABLE 19

No. M X₁ X₂ Y₁₁, Y₁₂ Y₁₃, Y₁₄ Y₁₅, Y₁₆ Y₁₇, Y₁₈ 137 Cu

—H —H, —H —H, —H —H, —H —H, —H 138 Cu

—H —H, —H —H, —H —H, —H —H, —H 139 Cu

—Cl —H, —H —H, —H —H, —H —H, —H 140 Cu

—H —H, —H —H, —H —H, —H —H, —H

TABLE 20

No. M X₁ X₂ Y₁₁, Y₁₂ Y₁₃, Y₁₄ Y₁₅, Y₁₆ Y₁₇, Y₁₈ 141 Cu

—H —H, —H —H, —H —H, —H —H, —H 142 Cu

—H —H, —H —H, —H —H, —H —H, —H 143 Cu

—H —H, —H —H, —H —H, —H —H, —H 144 Cu

—H —H, —H —H, —H —H, —H —H, —H 145 Cu —SO₂CH₂CH₂OCH₂CH₂CCH₂CH₂SO₃Li —H—H, —H —H, —H —H, —H —H, —H

In the following table, the introduction sites of the substituents (Xp1)and (Xp2) in the β-position substituents are not in order. TABLE 21M—Pc(Xp₁)_(m)(Xp₁)_(n) No. M Xp₁ m Xp₁ n 146 Cu

3

1 147 Cu —SO₂—NH—CH₂—CH₂SO₃Li 3

1 148 Cu

3 —SO₂NH—CH₂—CH₂—CH₂—SO₂—NH—CH₂—CH₂—O—CH₂—CH₂—OH 1 149 Cu

2 —SO₂—NH—CH₂—CH₂—CH₂—CO—N

CH₂—CH₂—OH)₂ 2 150 Cu —SO₂—NH—CH₂—CH₂—SO₂—NH—CH₂CH₂—COONa 3

1 151 Cu

3 —SO₂NH—CH₂—CH₂—O—CH₂—CH₂—OH 1 152 Cu

2.5 —SO₂—CH₂—CH₂—O—CH₂—CH₂—OH 1.5 153 Cu

2 —SO₂—CH₂—CH₂—CH₂—CO—N

CH₂—CH₂—OH)₂ 2 154 Cu —SO₂—CH₂—CH₂—CH₂—SO₃Li 3

1 155 Cu —SO₂—CH₂—CH₂—CH₂—COOK 2

2 156 Cu —SO₂—CH₂—CH₂—CH₂—SO₃Li 3

1 157 Cu —SO₂—CH₂—CH₂—O—CH₂—CH₂—SO₃Li 2

2

TABLE 22 M—Pc(Xp₁)_(m)(Xp₁)_(n) No. M Xp₁ m Xp₂ n 158 Cu

3

1 159 Cu —SO₂NHCH₂CH₂—SO₃Li 3

1 160 Cu —SO₂—CH₂—CH₂—O—CH₂—Ch₂—O—CH₂—CH₂—SO₃Na 3

1 161 Cu —SO₂CH₂CH₂CH₂SO₃Li 3

1 162 Cu —SO₂CH₂CH₂CH₂SO₃Li 2 —SO₂CH₂CH₂OCH₂CH₂OCH₂CH₂OH 2 163 Cu—SO₂CH₂CH₂CH₂SO₃K 3

1 164 Cu —SO₂CH₂CH₂CH₂SO₃Li 2 —SO₂CH₂CH₂CH₂SO₂H(CH₂CH₂OH)₃ 2 165 Cu—CO—NH—CH₂—CH₂—SO₃K 3 —CO—NH—CH₂—CH₂—O—CH₂—CH₂—OH 1 166 Cu—CO—NH—CH₂—CH₂—SO₂—NH—CH₂—CH₂—COONa 3

1 167 Cu

2.5 —CO—NH—CH₂—CH₂—CH₂—CO—N

CH₂—CH₂—OH)₂ 1.5 168 Cu

2 —CO—CH₂—CH₂—CH₂—CO—N

CH₂—CH₂—OH)₂ 2 169 Cu —CO₂—CH₂—CH₂—CH₂—SO₃Li 3

1 170 Cu —CO₂—CH₂—CH₂—CH₃COOK 2

2

TABLE 23 M—Pc(Xp₂)_(m)(Xp₂)_(n) No. M Xp₁ m Xp₂ n 171 Cu—CO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₂—CH₂—SO₃Na 3

1 172 Cu —SO₂CH₂CH₂OCH₂CH₂O—CH₂CH₂SO₃K 2

2 173 Cu

2

2 174 Cu

3

1 175 Cu —SO₂(CH₂)₃SO₂NH(CH₂)₃N(CH₂CH₂OH)_(t) 2

2 176 Cu

3

1 177 Cu —SO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₂ 2

1 178 Cu —SO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₂—CH₂—OH 3

1 179 Cu

2

2 180 Cu

3 —SO₂NH—CH₂—CH₂—SO₂NH—CH₂—CH₂—O—CH₂—CH₂—OH 1 181 Cu

3 —SO₂—CH₂—CH₂—CH₂—SO₂—NH—CH

CH₃)₂ 1 182 Cu

2.5

1.5

TABLE 24 M—Pc(Xp₁)_(m)(Xp₂)_(n) No. M Xp₁ m Xp₂ n 183 Cu

2 —SO₂—CH₂—CH₂—CH₂—SO₂—NH—(CH₂)₃—CH₂—O—CH₂CH₂—OH 2 184 Cu

3 —SO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₃ 1 185 Cu

3 —SO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₂—CH₂—O—CH₃ 1 186 Cu

3 —SO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₂—CH₂—OH 1 187 Cu—SO₂—CH₂—CH₂—CH₂—SO₂—NH—CH

CH₃)₂ 3

1 188 Cu

3 —CO₂—CH₂—CH₂—O—CH₂—CH₂—O—CH₃ 1 189 Cu —CO—NH—CH₂—CH₂—SO₂—NH—CH

CH₃)₂ 3

1 190 Cu

3 —CO—NH—CH₂—CH₂—O—CH₂—CH₂—O—CH₃ 1

The structure of the phthalocyanine compound represented byM-Pc(Xp₁)m(Xp₂)n in Tables 21 to 24 is as follows.

The phthalocyanine dye represented by the general formula (C-I) can besynthesized according to the patent cited above. The phthalocyanine dyerepresented by the general formula (C-II) can be synthesized by theaforementioned method as well as the method disclosed inJP-A-2001-226275, JP-A-2001-96610, JP-A-2001-47013 and JP-A-2001-193638.The starting material, intermediate dye and synthesis route are notlimited to those according to these methods.

The cyan ink composition comprises the phthalocyanine dye incorporatedtherein preferably in an amount of from 0.2% to 20% by weight, morepreferably from 0.5% to 15% by weight.

The phthalocyanine dye to be used in the invention is substantiallywater-soluble. The term “substantially water-soluble” as used herein ismeant to indicate that the dye can be dissolved in 20° C. water in anamount of not smaller than 2% by weight.

The ink composition for ink jet recording of the invention may compriseother cyan dyestuffs incorporated therein in combination with theaforementioned phthalocyanine dye (cyan dye).

Examples of cyan dyestuffs to be used in combination with thephthalocyanine dye include azomethine dyestuffs such as indoanilinedyestuff and indophenol dyestuff, polymethine dyestuffs such as cyaninedyestuff, oxonol dyestuff and melocyanine dyestuff, carbonium dyestuffssuch as diphenylmethane dyestuff, triphenylmethane dyestuff and xanthenedyestuff, phthalocyanine dyestuffs other than the compound of thegeneral formula (C-I) of the invention, anthraquinone dyestuffs, aryl orheterylazo dyestuffs having phenols, naphthols or anilines as couplingcomponents, and indigo-thioindigo dyestuffs. These dyestuffs may assumescyan only when chromophore is partly dissociated. In this case, thecounter cation may be an inorganic cation such as alkaline metal ion andammonium ion or an organic cation such as pyridinium ion and quaternaryammonium salt ion or may be contained in a polymer cation as a partialstructure.

The phthalocyanine dye represented by the general formula (C-I) can besynthesized according to the patent cited above. The phthalocyanine dyerepresented by the general formula (C-II) can be synthesized by themethod disclosed in JP-A-2001-226275, JP-A-2001-96610, JP-A-2001-47013and JP-A-2001-193638. The starting material, intermediate dye andsynthesis route are not limited to those according to these methods.

The various coloring agents are preferably incorporated in an amount offrom not smaller than 0.2 parts by weight to not greater than 20 partsby weight based on 100 parts by weight of the cyan ink. In theinvention, in the case where as inks having the same hue there are usedtwo or more different inks, the concentration of one ink is preferablyfrom 0.05 to 0.5 times that of the others.

The ink set of the invention may comprise the aforementioned specificyellow ink incorporated therein. Alternatively, other coloring materialsmay be properly used in combination with the aforementioned yellow dyeto obtain a full-color image or adjust the color tone, thereby preparingblack, cyan, magenta, yellow, red, green and blue inks of the inventionwhich can be then combined to provide an ink set suitable for theformation of a color image. As coloring agents to be used in thepreparation of other inks which form an ink set in combination with theyellow ink there may be used various dyestuffs (dye, pigment).

Examples of the dyestuffs which can be used in the ink for ink jetrecording of the invention will be given below.

Examples of yellow dyestuffs include aryl or heterylazo dyestuffs havingphenols, naphthols, anilines, pyrazolones, pyridones or closed-chaintype active methylene compounds as coupling components, azomethinedyestuffs having closed-chain type active methylene compounds ascoupling components, methine dyestuffs such as benzylidene dyestuff andmonomethine oxonol dyestuff, and quinone-based dyestuffs such asnaphthoquinone dyestuff and anthraquinone dyestuff. Other examples ofyellow dyestuffs include quinophthalone dyestuff, nitro-nitrosodyestuff, acridine dyestuff, and acridinone dyestuff. These dyestuffsmay assumes yellow only when chromophore is partly dissociated. In thiscase, the counter cation may be an inorganic cation such as alkalinemetal ion and ammonium ion or an organic cation such as pyridinium ionand quaternary ammonium salt ion or may be contained in a polymer cationas a partial structure.

Examples of magenta dyestuffs include aryl or heterylazo dyestuffshaving phenols, naphthols or anilines as coupling components, azomethinedyestuffs having pyrazolones or pyrazolotriazoles as couplingcomponents, methine dyestuffs such as arylidene dyestuff, styryldyestuff, melocyanine dyestuff and oxonol dyestuff, carbonium dyestuffssuch as diphenylmethane dyestuff, triphenylmethane dyestuff and xanthenedyestuff, quinone-based dyestuffs such as naphthoquinone, anthraquinoneand anthrapyridone, and condensed polycyclic dyestuffs such as dioxazinedyestuff. These dyestuffs may assumes magenta only when chromophore ispartly dissociated. In this case, the counter cation may be an inorganiccation such as alkaline metal ion and ammonium ion or an organic cationsuch as pyridinium ion and quaternary ammonium salt ion or may becontained in a polymer cation as a partial structure.

Examples of cyan dyestuff include azomethine dyestuffs such asindoaniline dyestuff and indophenol dyestuff, polymethine dyestuffs suchas cyanine dyestuff, oxonol dyestuff and melocyanine dyestuff, carboniumdyestuffs such as diphenylmethane dyestuff, triphenylmethane dyestuffand xanthene dyestuff, phthalocyanine dyestuffs, anthraquinonedyestuffs, aryl or heterylazo dyestuffs having phenols, naphthols oranilines as coupling components, and indigo-thioindigo dyestuffs. Thesedyestuffs may assumes cyan only when chromophore is partly dissociated.In this cases the counter cation may be an inorganic cation such asalkaline metal ion and ammonium ion or an organic cation such aspyridinium ion and quaternary ammonium salt ion or may be contained in apolymer cation as a partial structure.

Alternatively, a black dye such as polyazo dye or a carbon blackdispersion may be used.

In the invention, the dye, if it is oil-soluble, is preferably used incombination with a high boiling organic solvent. The boiling point ofthe high boiling organic solvent to be used in the invention is notlower than 150° C., preferably not lower than 170° C.,

Examples of the high boiling organic solvent employable herein includephthalic acid esters (e.g., dibutyl phthalate, dioctyl phthalate,dicyclohexylphthalate, di-2-ethylhexylphthalate, decyl phthalate,bis(2,4-di-tert-amylphenyl)isophthalate,bis(1,1-diethylpropyl)phthalate), phosphoric or phosphonic acid esters(e.g., diphenyl phosphate, triphenyl phosphate, tricresyl phosphate2-ethylhexyl diphenyl phosphate, dioctyl butyl phosphate, tricyclohexylphosphate, tri-2-ethylhexyl phosphate, tridodecyl phosphate,di-2-ethylhexyl phenyl phosphate), benzoic acid esters (e.g.,2-ethylhexyl benzoate, 2,4-dichlorobenzoate, dodecyl benzoate,2-ethylhexyl-p-hydroxybenzoate), asides (e.g., N,N-diethyldodecaneamide,N,N-diethyllaurylamide), alcohols or phenols (e.g., isostearyl alcohol,2,4-di-tert-amylphenol), aliphatic esters (e.g., dibutoxyethylsuccinate, di-2-ethylhexyl succinate, 2-hexyldecyl tetradecanoate,tributyl citrate, diethyl azelate, isostearyl lactate, trioctylcitrate), aniline derivatives (e.g.,N,N-dibutyl-2-butoxy-5-tert-octylaniline), chlorinated paraffins (e.g.,paraffins having a chlorine content of from 10% to 80%), trimesic acidesters (e.g., tributyl trimesate), dodecyl benzene, diisopropylenenaphthalene, phenols (e.g., 2,4-di-tert-amylphenol, 4-dodecyloxyphenol,4-dodecyloxycarbonylphenol, 4-(4-dodecyloxy phenylsulfonyl)phenol),carboxylic acids (e.g., 2-(2,4-di-tert-amylphenoxybutyric acid,2-ethoxyoctanedecanoic acid), and alkylphosphoric acids (e.g.,di-2(ethylhexyl)phosphoric acid, dipheylphosphoric acid). As anauxiliary solvent there may be additionally used an organic solventhaving a boiling point of from not lower than 30° C. to not higher thanabout 160° C. (e.g., ethyl acetate, butyl acetate, ethyl propionate,methyl ethyl ketone, cyclohexanone, 2-ethoxyethylacetate,dimethylformamide). The high boiling organic solvent may be used in anamount of from 0 to 2.0 times, preferably from 0 to 1.0 times that ofthe coupler.

These high boiling organic solvents may be used singly or in admixtureof two or more thereof (e.g., tricresyl phosphate and dibutyl phthalate,trioctyl phosphate and di(2-ethylhexyl) sebacate, dibutyl phthalate andpoly(N-t-butylacrylamide)).

For examples of compounds other than the aforementioned high boilingorganic solvents to be used in the invention and/or methods for thesynthesis of these high boiling organic solvents, reference can be madeto U.S. Pat. Nos. 2,322,027, 2,533,514, 2,772,163, 2,835,579, 3,594,171,3,676,137, 3,689,271, 3,700,454, 3,748,141, 3,764,336, 3,765,897,3,912,515, 3,936,303, 4,004,928, 4,080,209, 4,127,413, 4,193,802,4,207,393, 4,220,711, 4,239,851, 4,278,757, 4,353,979, 4,363,873,4,430,421, 4,430,422, 4,464,464, 4,483,918, 4,540,657, 4,684,606,4,728,599, 4,745,049, 4,935,321, 5,013,639, European Patents 276,319A,286,253A, 289,820A, 309,158A, 309,159A, 309,160A, 509,31A, 510,576A,East German Patents 147,009, 157, 147, 159, 573, 225,240A, BritishPatent 2,091,124A, JP-A-48-47335, JP-A-50-26530, JP-A-51-25133,JP-A-51-26036, JP-A-51-27921, JP-A-51-27922, JP-A-51-149028,JP-A-52-46816, JP-A-53-1520, JP-A-53-1521, JP-A-53-15127,JP-A-53-146622, JP-A-54-91325, JP-A-54-106228, JP-A-54-118246,JP-A-55-59464, JP-A-56-64333, JP-A-56-81836, JP-A-59-204041,JP-A-61-84641, JP-A-62-118345, JP-A-62-247364, JP-A-63-167357,JP-A-63-214744, JP-A-63-301941, JP-A-64-9452, JP-A-64-9454,JP-A-64-68745, JP-A-1-101543, JP-A-1-102454, JP-A-2-792, JP-A-2-4239,JP-A-2-43541, JP-A-4-29237, JP-A-4-30165, JP-A-4-232946, andJP-A-4-346338.

The aforementioned high boiling organic solvents are used in an amountof from 0.1 to 3.0 times, preferably from 0.5 to 1.0 times that of thedye by weight.

In the invention, the hydrophobic dye or the high boiling organicsolvent or other additives, if they are hydrophobic, are used in theform of emulsion dispersion in an aqueous medium. During emulsiondispersion, a low boiling organic solvent may be used in some cases fromthe standpoint of emulsifiability. As such a low boiling organic solventthere may be used an organic solvent having a boiling point of fromabout 30° C. to 150° C. at atmospheric pressure. Preferred examples ofthe organic solvent employable herein include esters (e.g., ethylacetate, butyl acetate, ethyl propionate, β-ethoxyethyl acetate, methylcellosolve acetate), alcohols (e.g., isopropyl alcohol, n-butyl alcohol,secondary butyl alcohol), ketones (e.g., methyl isobutyl ketone, methylethyl ketone, cyclohexanone), amides (e.g., dimethylformamide,N-methylpyrrolidone), and ethers (e.g., tetrahydrofurane, dioxane).However, the invention is not limited to these organic solvents.

The emulsion dispersion is effected to disperse an oil phase having adye dissolved in a high boiling organic solvent optionally mixed with alow boiling organic solvent in an aqueous phase mainly composed of waterto make minute oil droplets of oil phase. During this procedure,additives such as surface active agent, wetting agent, dye stabilizer,emulsion stabilizer, preservative and antifungal agent described latermay be added to either or both of the aqueous phase and the oil phase asnecessary.

The emulsification is normally accomplished by adding the oil phase tothe aqueous phase. Alternatively, a so-called phase inversionemulsification method involving the dropwise addition of an aqueousphase to an oil phase is preferably used.

The emulsion dispersion of the invention may be effected with varioussurface active agents. Preferred examples of the surface active agentsemployable herein include anionic surface active agents such asaliphatic acid salt, alkylsulfuric acid ester, alkylbenzenesulfonate,alkylnaphthalenesulfonate, dialkylsulfosuccinate, alkylphosphoric acidesters, naphthalenesulfonic acid-formalin condensate andpolyoxyethylenealkylsulfuric acid ester, and nonionic surface activeagents such as polyoxyethylenealkyl ether, polyoxyethylenealkylallylether, polyoxyethylenealiphatic acid ester, sorbitanaliphatic acidester, polyoxyethylenesorbitanaliphatic acid ester,polyoxyethylenealkylamine, glycerinaliphatic acid ester andoxyethyleneoxypropylene block copolymer. Alternatively, SURPYNOLS(produced by Air Products & Chemicals Inc.), which are acetylene-basedpolyoxyethylene oxide surface active agents, are preferably used aswell. Further, amineoxide-based amphoteric surface active agents such asN,N-dimethyl-N-alkylamine oxide may be used. Those listed as surfaceactive agents in JP-A-59-157,636, pp. 37-38, Research Disclosure No.308119 (1989), Japanese Patent Application No. 2001-11821, JapanesePatent Application No. 2001-11822, Japanese Patent Application No.2001-80690, and Japanese Patent Application No. 2001-80659 may be used.

For the purpose of stabilizing the ink shortly after emulsification, theaforementioned surface active agents may be used in combination with awater-soluble polymer. As such a water-soluble polymer there may bepreferably used a polyvinyl alcohol, polyvinyl pyrrolidone, polyethyleneoxide, polyacrylic acid, polyacrylamide or copolymer thereof. Further,natural water-soluble polymers such as polysaccharides, casein andgelatin may be preferably used. For the purpose of stabilizing the dyedispersion, polyvinyls obtained by the polymerization of acrylic acidesters, methacrylic acid esters, vinyl esters, acrylamides,methacrylamides, olefins, styrenes, vinylethers or acrylonitriles,polyurethanes, polyesters, polyamides, polyureas, polycarbonates, etc.,which are substantially insoluble in an aqueous medium, may be used.These polymers preferably have —SO₃ ⁻ or —COO⁻. In the case where thesepolymers substantially insoluble in an aqueous medium are used, they arepreferably used in an amount of not greater than 20% by weight,preferably not greater than 10% by weight based on the amount of thehigh boiling organic solvent.

In the case where emulsion dispersion is effected to disperse thehydrophobic dye in the solvent to make an aqueous ink, a particularlyimportant factor is control over the particle size of the aqueous ink.In order to enhance the color purity or density during the formation ofan image by ink ejection, it is essential to reduce the average particlesize. The volume-average particle diameter of the aqueous ink ispreferably from not smaller than 5 nm to not greater than 100 nm.

It was also made obvious that the presence of coarse particles has anextremely great effect on the printing properties. In other words,coarse particles clog the head nozzle. Even if coarse particles don't goso far as to clog the head nozzle, the ink cannot be ejected or can bedeviated when ejected, giving a serious effect on the printingproperties. In order to prevent this trouble, it is important to keepthe number of particles having a diameter of not smaller than 5 μm andnot smaller than 1 μm in the resulting ink to 10 or less and 1,000 orless, respectively.

The removal of these coarse particles can be accomplished by any knownmethod such as centrifugal separation method and precision filtrationmethod. The separation step may be effected shortly after emulsiondispersion or shortly before the filling of the emulsion dispersioncomprising various additives such as wetting agent and surface activeagent in the ink cartridge.

As an effective unit for reducing the average particle diameter ofparticles and eliminating coarse particles there may be used amechanical emulsifier.

As such an emulsifier there may be used any known device such as simplestirrer, impeller type agitator, in-line agitator, mill type agitator(e.g., colloid mill) and ultrasonic agitator. The use of a high pressurehomogenizer is particularly preferred.

For the details of the mechanism of high pressure homogenizer, referencecan be made to U.S. Pat. No. 4,533,254, JP-A-6-47264, etc. Examples ofcommercially available high pressure homogenizers include Gaulinhomogenizer (produced by A. P. V GAULLE INC.), microfluidizer (producedby MICROFLUIDEX INC.) and altimizer (produced by SUGINO MACHINELIMITED).

In recent years, a high pressure homogenizer having a mechanism foratomizing a material in a ultrahigh-pressure jet stream as disclosed inU.S. Pat. No. 5,720,551 is particularly useful in the emulsiondispersion of the invention. An example of the emulsifier using aultrahigh jet stream it De BES2000 (produced by BEE INTERNATIONAL LTD.).

The pressure at which emulsion is carried out by a high pressureemulsion disperser is not lower than 500 bar (5×10⁷ Pa), preferably notlower than 600 bar (6×10⁷ Pa), more preferably not lower than 1,800 bar(1.8×10⁸ Pa).

For example, the combined use of two or more emulsifiers as in a methodinvolving the emulsification by an agitated emulsifier followed by thepassage through a high pressure homogenizer is particularly preferred.Alternatively, a method is preferably used which comprises effecting theemulsion of the material using such an emulsifier, adding additives suchas wetting agent and surface active agent, and then passing the inkcomposition again through the high pressure homogenizer before beingfilled in the cartridge.

In the case where the dye composition comprises a low boiling organicsolvent incorporated therein in addition to the high boiling organicsolvent, it is preferred to remove the low boiling organic solvent formthe standpoint of emulsion stability and safety/hygiene. The removal ofthe low boiling solvent can be accomplished by any known method such asevaporation method, vacuum evaporation method and ultrafiltration methoddepending on the solvent to be removed. The step of removing the lowboiling organic solvent is preferably effected as rapidly as possibleshortly after emulsification.

Examples of the water-soluble organic solvent employable herein Includealcohols (e.g., methanol, ethanol, propanol, isopropanol, butanol,isobutanol, sec-butanol, t-butanol, pentanol, hexanol, cyclohexanol,benzyl alcohol), polyvalent alcohols (e.g., ethylene glycol, diethyleneglycol, triethylene glycol, polyethylene glycol, propylene glycol,dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol,pentanediol, glycerin, hexanetriol, thiodiglycol), glycol derivatives(e.g., ethylene glycol monomethyl ether, ethylene glycol monoethylether, ethylene glycol monobutyl ether, diethylene glycol monomethylether, diethylene glycol monobutyl ether, propylene glycol monomethylether, propylene glycol monobutyl ether, dipropylene glycol monomethylether, triethylene glycol monomethyl ether, ethylene glycol diacetate,ethylene glycol monomethyl ether acetate, triethylene glycol monamethylether, triethylene glycol monoethyl ether, ethylene glycolmonophenylether), amines (e.g., ethanolamine, diethanolamine, triethanolamine,N-methyldiethanolamine, N-ethyldiethanolamine, morpholine,N-ethylmorpholine, ethylene diamine, diethylene triamine, triethylenetetramine, polyethyleneimine, tetramethylpropylenediamine), and otherpolar solvents (e.g., formamide, N,N-dimethylformamide,N,N-dimethylacetamide, dimethylsulfoxide, sulfolane, 2-pyrrolidone,N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-oxazolidone,1,3-dimethyl-2-imidazolidinone, acetonitrile, acetone). Two or more ofthe water-miscible organic solvents may be used in combination.

The dispersion of colored particles obtained in the invention, if usedas an ink for ink jet recording, may comprise properly selectedadditives incorporated therein in a proper amount such as dryinginhibitor for preventing the clogging of the ejection nozzle with driedink, penetration accelerator for helping the ink to penetrate in thepage, ultraviolet absorber, oxidation inhibitor, viscosity adjustor,surface tension adjustor, dispersant, dispersion stabilizer, antifungalagent, rust preventive, pH adjustor, anti-foaming agent and chelatingagent.

As the drying inhibitor there is preferably used a water-soluble organicsolvent having a lower vapor pressure than water. Specific examples ofthe water-soluble organic solvent include polyvalent alcohols such asethylene glycol, propylene glycol, diethylene glycol, polyethyleneglycol, thiodiglycol, dithiodigycol, 2-methyl-1,3-propanediol,1,2,6-hexanetriol, acetylene glycol derivative, glycerin andtrimethylolpropane, lower alkylethers of polyvalent alcohol such asethylene glycol monomethyl (or ethyl) ether, diethylene glycolmonomethyl (or ethyl) ether and triethylene glycol monoethyl(orbutyl)ether, heterocyclic compounds such as 2-pyrrolidone,N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone andN-ethylmorpholine, sulfur-containing compounds such as sulfolane,dimethylsulfoxide and 3-sulfolene, polyfunctional compounds such asdiacetone alcohol and diethanolamine, and urea derivatives. Preferredamong these water-soluble organic solvents are polyvalent alcohols suchas glycerin and diethylene glycol. These drying inhibitors may be usedsingly or in combination of two or more thereof. These drying inhibitorsare preferably incorporated in the ink in an amount of from 10% to 50%by weight.

Examples of the penetration accelerator employable herein includealcohols such as ethanol, isopropanol, butanol, di(tri)ethylene glycolmonobutyl ether and 1,2-hexanediol, sodium laurylsulfate, sodium oleate,and nonionic surface active agents. These penetration accelerators canexert a sufficient effect when incorporated in the ink in an amount offrom 10% to 30% by weight. These penetration accelerators are preferablyused in an amount such that no printing run or print through occurs.

Examples of the ultraviolet absorber to be used to enhance thepreservability of the image include benzotriazole-based compounds asdisclosed in JP-A-58-185677, JP-A-61-190537, JP-A-2-782, JP-A-5-197075and JP-A-9-34057, benzophenone-based compounds as disclosed inJP-A-46-2784, JP-A-5-194483 and U.S. Pat. No. 3,214,463, cinnamicacid-based compounds as disclosed in JP-B-48-30492, JP-A-56-21141 andJP-A-10-88106, triazine-based compounds as disclosed in JP-A-4-298503,JP-A-8-53427, JP-A-8-239368, JP-A-10-182621 and JP-T-1-543210, compoundsas disclosed in Research Disclosure No. 24239, and compounds whichabsorb ultraviolet rays to emit fluorescence, i.e., so-calledfluorescent brighteners, such as stilbene-based and benzoxazole-basedcompounds.

As the oxidation inhibitor to be used to enhance the imagepreservability there may be used any of various organic and metalcomplex-based discoloration inhibitors. Examples of the organicdiscoloration inhibitors include hydroquinones, alkoxyphenols,dialkoxyphenols, phenols, anilines, amines, indanes, chromans,alkoxyanilines, and heterocyclic compounds. Examples of the metalcomplex-based discoloration inhibitors include nickel complex, and zinccomplex. Specific examples of these oxidation inhibitors includecompounds listed in the patents cited in Research Disclosure No. 18716,Articles VI-I and J, Research Disclosure No. 15162, Research DisclosureNo. 15716, left column, page 650, Research Disclosure No. 36544, page527, Research Disclosure No. 307105, page 872, and Research DisclosureNo. 15162, and compounds included in the general formula and examples ofrepresentative compounds listed in JP-A-62-215272, pp. 127-137. Examplesof the antifungal agent include sodium dehydroacetate, sodium benzoate,sodium pyridinethione-1-oxide, ethyl p-hydroxybenzoate,1,2-benzoisothiazoline-3-one, and salts thereof. These antifungal agentsare preferably incorporated in the ink in an amount of from 0.02% to5.00% by weight. For the details of these antifungal agents, referencecan be made to “Bokin Bobizai Jiten (Dictionary of Anti-bacterial andAntifungal Agents”), compiled by Dictionary Compilation Committee of TheSociety for Antibacterial and Antifungal Agents, Japan.

Examples of the rust preventive employable herein include acidicsulfites, sodium thiosulfate, ammonium thioglycolate,diisopropylammonium nitrite, pentaerthyritol tetranitrate,dicyclohexylammonium nitrite, and benzotriazole. These rust preventivesare preferably incorporated in the ink in an amount of from 0.02% to5.00% by weight.

The pH adjustor is preferably used from the standpoint of pH adjustment,provision of dispersion stability, etc. The pH adjustor is preferablyadded to make pH 4.5 to 10.0, more preferably pH 6 to 10.0. Examples ofthe pH adjustor employable herein include basic pH adjustors such asorganic base and inorganic alkali, and acidic pH adjustors such asorganic acid and inorganic acid.

Examples of the organic base include triethanolamine, diethanolamine,N-methyldiethanolamine, and diethanolamine. Examples of the inorganicalkali include hydroxide of alkali metal (e.g., sodium hydroxide,lithium hydroxide, potassium hydroxide), carbonate of alkali metal(e.g., sodium carbonate, sodium hydrogencarbonate), and ammonia.

Examples of the organic acid include acetic acid, propionic acid,trifluoroacetic acid, and alkylsulfonic acid. Examples of the inorganicacid include hydrochloric acid, sulfuric acid, and phosphoric acid.

Examples of the surface tension adjustor employable herein includenonionic, cationic and anionic surface active agents. Examples of theanionic surface active agent include aliphatic acid salts, alkylsulfuricacid esters, alkylbenzenesulfonates, alkylnapthalenesulfonates,dialkylsulfosuccinates, alkylphosphoric acid esters, naphthalenesulfonicacid-formalin condensates, and polyoxyethylenealkylsulfuric acid esters.Examples of the nonionic surface active agent includepolyoxyethylenealkyl ethers, polyoxyethylenealkylallyl ethers,polyoxyethylenealiphatic acid esters, sorbitanaliphatic acid esters,polyoxyethylenesorbitanaliphatic acid esters,polyoxyethylenealkylamines, glycerinaliphatic acid esters, andoxyethyleneoxypropylene block copolymers. SURFYNOLS (produced by AirProducts a Chemicals Inc.), which are acetylene-based polyoxyethyleneoxide surface active agents, are preferably used as well. Further, amineoxide-based amphoteric surface active agents such asN,N-dimethyl-N-alkylamine oxide are preferred. Moreover, those listed assurface active agents in JP-A-59-157,636, pp. 37-38, and ResearchDisclosure No. 308119, 1989, may be used. The surface tension,regardless of which it is static or dynamic, of the ink to be used inthe invention is preferably from 20 to not greater than 50 mN/m, morepreferably from 20 to not greater than 40 mN/m at 25° C. When thesurface tension of the ink exceeds 50 mN/m, the resulting ink exhibits adrastic deterioration in print quality such as ejection stability andresistance to running and whisker during color mixing. On the contrary,when the surface tension of the ink falls below 20 mN/m, the resultingink can be attached to hard surface when ejected, causing defectiveprinting.

The ink of the invention exhibits a viscosity of from 1 to 20 mPa·s,more preferably from 2 to 15 mPa·s particularly from 2 to 10 mPa·s at2500. When the viscosity of the ink exceeds 30 mPa·s, the resultingrecorded image can be fixed only at a reduced rate. Further, theresulting ink exhibits a deteriorated ejectability. On the contrary,when the viscosity of the ink falls below 1 mPa·s, the resultingrecorded image runs and thus exhibits a reduced quality.

The adjustment of viscosity can be arbitrarily carried out bycontrolling the added amount of the ink solvent. Examples of the inksolvent employable herein include glycerin, diethylene glycol,triethanolamine, 2-pyrrolidone, diethylene glycol monobutyl ether, andtriethylene glycol monobutyl ether.

Further, a viscosity adjustor may be used. Examples of the viscosityadjustor employable herein include celluloses, water-soluble polymerssuch as polyvinyl alcohol, and nonionic surface active agents. For thedetails of these viscosity adjustors, reference can be made to “NendoChousei Gijutsu (Technology for Viscosity Adjustment)”, Gijutsu JohoKyoukai, Article 9, 1999, and “Inku Jetto Purintayou Kemikaruzu (98zouho)—Zairyou no Kaihatsu Doko/Tenbo Chousa (chemicals for Ink JetPrinter (98 enlarged edition)—Research on Trend and View of Developmentof Materials)”, CMC, pp. 162-174, 1997.

In the invention, a dispersion of polymer particles may be used. For thedetails of the dispersion of polymer particles, reference can be made toJapanese Patent Application No. 2001-63780.

In the invention, as the dispersant and dispersion stabilizer there maybe used the aforementioned various cationic, anionic and nonionicsurface active agents as necessary. As the anti-forming agent there maybe used a fluorine-based or silicone-based compound or a chelating agentsuch as EDTA as necessary.

The ink jet recording method to which the ink of the invention isapplied is not limited. The ink of the invention may be used in anyknown recording method such as electrostatic control method whichutilizes electrostatic attraction to eject ink, drop-on-demand method(pressure pulse method) utilizing vibrational pressure of piezoelectricelement, acoustic ink jet method which comprises converting electricalsignal to acoustic beam with which the ink is irradiated to produce aradiation pressure that is utilized to eject the ink and thermal ink jet(bubble jet) method which comprises heating the ink to form bubbles thatraise the pressure to eject the ink.

Examples of the ink jet recording method include a method whichcomprises ejecting many portions of an ink having a low concentrationcalled photoink in a small volume, a method which comprises using aplurality of inks having substantially the same hue but differentdensities to improve the image quality, and a method involving the useof a colorless transparent ink.

As the ink jet recording method and ink cartridge suitable for use inthe invention there may be used any known ink jet recording method andink cartridge. For the details of the ink jet recording method and inkcartridge, reference can be made to JP-A-2000-198958.

The ink set and ink cartridge of the invention can be used to form animage on a known recording material, i.e., ordinary paper, resin-coatedpaper such as paper dedicated for ink jet recording disclosed inJP-A-8-169172, JP-A-8-27693, JP-A-2-276670, JP-A-7-276789,JP-A-9-323475, JP-A-62-238783, JP-A-10-153989, JP-A-10-217473,JP-A-10-235995, JP-A-10-337947, JP-A-10-217597 and JP-A-10-337947, film,electrophotographic paper, cloth, glass, metal, porcelain, etc.

The recording paper and recording film which is a reflection type mediumto be used in the ink jet recording method using the ink of theinvention will be described hereinafter.

As the support in the recording paper or recording film there may beused one obtained by processing a chemical pulp such as LBKP and NBKP, amechanical pulp such as GP, PGW, RMP, TMF, CTMP, CMP and CGP, used paperpulp such as DIP or the like, optionally mixed with known additives suchas pigment, binder, sizing agent, fixing agent, cationic agent and paperstrength improver, through various paper machines such as foundrinierpaper machine and cylinder paper machine. As the support there may beused either a synthetic paper or plastic film sheet besides thesesupport materials. The thickness of the support is preferably from 10 μmto 250 μm. The basis weight of the support is preferably from 10 to 250g/m². An ink-receiving layer and a back coat layer may be provided onthe support directly or with a size press or anchor coat layer ofstarch, polyvinyl alcohol or the like interposed therebetween to preparea material for receiving the ink of the invention. The support may befurther subjected to leveling using a calendering machine such asmachine calender, TG calender and soft calender. As the support there ispreferably used a paper or plastic film laminated with a polyolefin(e.g., polyethylene, polystyrene, polybutene, copolymer thereof) orpolyethylene terephthalate on both sides thereof. The polyolefinpreferably comprises a white pigment (e.g., titanium oxide, zinc oxide)or a tinting dye (e.g., cobalt blue, ultramarine, neodymium oxide)incorporated therein.

The ink-receiving layer to be provided on the support comprises apigment or aqueous binder incorporated therein. As such a pigment thereis preferably used a white pigment. Examples of the white pigmentemployable herein include inorganic white pigments such as calciumcarbonate, kaolin, talc, clay, diatomaceous earth, synthetic amorphoussilica, aluminum silicate, magnesium silicate, calcium silicate,aluminum hydroxide, alumina, lithopone, zeolite, barium sulfate, calciumsulfate, titanium dioxide, zinc sulfate and zinc carbonate, and organicpigments such as styrene-based pigment, acrylic pigment, urea resin andmelamine resin. As the white pigment to be incorporated in theink-receiving layer there is preferably used a porous inorganic pigment,particularly a synthetic amorphous silica having a large pore area, etc.As the synthetic amorphous silica there may be also used anhydroussilicate obtained by dry method or hydrous silicate obtained by wetmethod, particularly hydrous silicate. These pigments may be used incombination of two or more thereof.

Examples of the aqueous binder to be incorporated in the ink-receivinglayer include water-soluble polymers such as polyvinyl alcohol,silanol-modified polyvinyl alcohol, starch, cationated starch, casein,gelatin, carboxymethyl cellulose, hydroxyethyl cellulose, polyvinylpyrrolidone, polyalkylene oxide and polyalkylene oxide derivative, andwater-dispersible polymers such as styrene butadiene latex and acrylemulsion. These aqueous binders may be used singly or in combination oftwo or tore thereof. In the invention, particularly preferred amongthese aqueous binders are polyvinyl alcohol and silanol-modifiedpolyvinyl alcohol from the standpoint of adhesion to pigment andexfoliation resistance of ink-receiving layer.

The ink-receiving layer may comprise a mordant, a waterproofing agent, alight-resistance improver, a surface active agent, a film hardener andother additives incorporated therein besides the pigments and aqueousbinders.

The mordant to be incorporated in the ink-receiving layer is preferablypassivated. To this end, a polymer mordant is preferably used.

For the details of the polymer mordant, reference can be made toJP-A-48-28325, JP-A-54-74430, JP-A-54-124726, JP-A-55-22766,JP-A-55-142339, JP-A-60-23850, JP-A-60-23851, JP-A-60-23852,JP-A-60-23853, JP-A-60-57836, JP-A-60-60643, JP-A-60-118834,JP-A-60-122940, JP-A-60-122941, JP-A-60-122942, JP-A-60-235134,JP-A-1-161236, U.S. Pat. Nos. 2,484,430, 2,548,564, 3,148,061,3,309,690, 4,115,124, 4,124,386, 4,193,800,4,273,853, 4,282,305 and4,450,224. An image-receiving material containing a polymer mordantdisclosed in JP-A-1-161236, pp. 212 to 215. The use of the polymermordant disclosed in the above cited patent makes it possible to obtainan image having an excellent quality and hence improve thelight-resistance of the image.

The waterproofing agent can be used to render the image waterproof. Assuch a waterproofing agent there is preferably used a cationic resin inparticular. Examples of such a cationic resin include polyamidepolyamine epichlorohydrin, polyethylenimine, polyamine sulfone, dimethyldiallyl ammonium chloride polymer, cation polyacrylamide, and colloidalsilica. Particularly preferred among these cationic resins is polyamidepolyamine epichlorohydrin. The content of such a cation resin ispreferably from 1% to 15% by weight, particularly from 3% to 10% byweight based on the total solid content of the ink-receiving layer.

Examples of the light-resistance improver employable herein include zincsulfate, zinc oxide, hindered amine-based oxidation inhibitor,benzophenone-based ultraviolet absorber, and benzotriazole-basedultraviolet absorber. Particularly preferred among theselight-resistance improvers is zinc sulfate.

The surface active agent acts as a coating aid, releasability improver,slipperiness improver or antistat. For the details of the surface activeagent, reference can be made to JP-A-62-173463 and JP-A-62-183457.

An organic fluoro-compounds may be used instead of the surface activeagent. The organic fluoro-compound is preferably hydrophobic. Examplesof the organic fluoro-compound include fluorine-based surface activeagents, oil-based fluorine compounds (e.g., fluorine-based oil), andsolid fluorine-based compound resins (e.g., tetrafluoroethylene resin).For the details of the organic fluoro-compound, reference can be made toJP-B-57-9053 (8th to 17th columns), JP-A-61-20994, and JP-A-62-135826.

As the film hardener there may be used any of materials disclosed inJP-A-1-161236, page 222.

Other examples of additives to be incorporated in the ink-receivinglayer include pigment dispersants, thickening agents, antifoamingagents, dyes, fluorescent brighteners, preservatives, pH adjustors,matting agents, and film hardeners. There may be provided one or twoink-receiving layers.

The recording paper and recording film may comprise a back coat layerprovided thereon. Examples of the components which can be incorporatedin the back coat layer include white pigments, aqueous binders, andother components. Examples of the white pigments to be incorporated inthe back coat layer include inorganic white pigments such as lightcalcium carbonate, heavy calcium carbonate, kaolin, talc, calciumsulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide,zinc carbonate, satin white, aluminum silicate, diatomaceous earth,calcium silicate, magnesium silicate, synthetic amorphous silica,colloidal silica, colloidal alumina, pseudo-boehmite, aluminumhydroxide, alumina, lithopone, hydrated halloysite, magnesium carbonateand magnesium hydroxide, and organic pigments such as styrene-basedplastic pigment, acrylic plastic pigment, polyethylene, microcapsule,urea resin and melamine resin.

Examples of the aqueous binder to be incorporated in the back coat layerinclude water-soluble polymers such as styrene/maleate copolymer,styrene/acrylate copolymer, polyvinyl alcohol, silanol-modifiedpolyvinyl alcohol, starch, cationated starch, casein, gelatin,carboxymethyl cellulose, hydroxyethyl cellulose andpolyvinylpyrrolidone, and water-dispersible polymers such asstyrenebutadiene latex and acryl emulsion. Examples of other componentsto be incorporated in the back coat layer include antifoaming agents,foaming inhibitors, dyes, fluorescent brightening agents, preservatives,and waterproofing agents.

The layers (including back layer) constituting the ink jet recordingpaper and film may comprise a polymer latex incorporated therein. Thepolymer latex is used for the purpose of improving physical propertiesof film, e.g., stabilizing dimension, inhibiting curling, adhesion andfilm cracking. For the details of the polymer latex, reference can bemade to JP-A-62-245258, JP-A-62-1316648, and JP-A-62-110066. Theincorporation of a polymer latex having a glass transition temperatureas low as not higher than 40° C. in a layer containing a mordant makesit possible to prevent the cracking or curling of the layer. Theincorporation of a polymer latex having a high glass transitiontemperature, too, in the back layer makes it possible to prevent thecurling of the back layer.

The image formed on the aforementioned recording paper or film with theink set or ink cartridge of the invention exhibits a high fastness andthus can provide an extremely excellent ink-recorded matter.

EXAMPLE

The invention will be further described in the following examples, butthe invention is not construed as being limited thereto.

Example 1

To the following components was added deionized water to make 1 l. Themixture was then heated to a temperature of from 30° C. to 40° C. withstirring for 1 hour. Thereafter, the solution was adjusted to pH 9 witha 10 mol/l potassium hydroxide, and then filtered through a microfilterhaving an average pore diameter of 0.25 μm under reduced pressure toprepare a yellow ink solution. Dye (T-3) 14.7 g Dye (T-4) 14.0 gDiethylene glycol   85 g Urea — Glycerin  150 g Triethylene glycolmonobutyl ether  180 g Diethylene glycol monobutyl ether — 2-Pyrrolidone— Surfynol 465 (produced by Air Products & — Chemicals Inc.) SurfynolSTG  8.5 g Triethanolamine  0.9 g Benzotriazole 0.06 g PROXEL XL2  1.5 g

Subsequently, to these components were added dyes and additives toprepare a light cyan, a cyan ink, a light magenta ink, a magenta ink anda black ink from which ink sets 101 having the concentration set forthin Table A were then prepared. TABLE A Light Light cyan Cyan magentaMagenta Yellow Black Dye (g/l) T-2 T-2 T-1 T-1 T-3 T-5 (8.75) (35.0)(7.5) (30.0) (14.7) (20.0) T-4 T-6 (14.0) (20.0) T-7 (20.0) T-3 (20.0)Diethylene glycol 200 130 150 110  85  20 (g/l) Urea — —  37  46 — —Glycerin 150 180 130 160 150 120 (g/l) Triethylene glycol 130 140 130140 180 — monobutyl ether (g/l) Diethylene glycol — — — — — 230monobutyl ether (g/l) 2-Pyrroli-done — — — — —  81 (g/l) Surfynol 465 9.8  10.5  10.5  10.0 — — (g/l) Surfynol STG — — — —  8.5  9.8 (g/l)Triethanol amine  6.0  6.3  6.9  7.0  0.9  17.9 (g/l) Benzotriazole 0.08  0.08  0.08  0.07  0.06  0.06 (g/l) Proxel XL2  1.1  1.2  3.5  1.5 1.5  1.1 (g/l) T-1

T-2

T-3

T-4

T-5

T-6

T-7

Subsequently, ink sets 102 to 105 were prepared in the same manner as inthe ink set 101 except that the formulation of the dyes used werechanged as set forth in Table B. In the case where the dyes werechanged, they were used in equimolecular amounts and their concentrationwas adjusted such that the transmission density of the various inksolutions was the same as in the ink set 101. In the case where aplurality of dyes were used in combination, they were used inequimolecular amounts. TABLE B Light Light Ink set cyan Cyan magentaMagenta Yellow Remarks 101 T-2 T-2 T-1 T-1 T-3 Comparative T-4 102 144144 a-36 a-36 YI-50 Inventive 103 145 144 a-36 a-36 YI-51 Inventive 104144 137 b-5  d-1  YI-50 Inventive 142 c-3  e-4  YI-51 105 T-2 T-2 T-1T-1 T-3 Inventive 144 144 a-36 a-36 YI-58

Subsequently, the ink sets 101 to 105 were each packed in the cartridgeof a Type PM770C ink jet printer (produced by EPSON CO., LTD.) by whichan image was then printed on a PM photographic paper for ink jet printerproduced by EPSON Co., LTD.). Then, the following properties wereevaluated.

1) For the evaluation of printing properties (1), the cartridge wasmounted on the printer. The ejection of ink through all the nozzles wasthen confirmed. An image was then printed on 50 sheets of A4 size paper.The printer matter was then evaluated for disturbance in print.

A; No disturbance in print between the beginning and the end ofprinting;

B: Some disturbance in print

C: Disturbance in print between the beginning and the end of printing

2) For the evaluation of printing properties (2), the cartridge wasallowed to stand at 60° C. for 10 days. The printed matter was thenevaluated for disturbance in print in the same manner as in the printingproperties (1).

3) For the evaluation of dryability, the images which had just beenformed were touched with a finger. The finger was then visually observedfor stain.

4) For the evaluation of running of fine line, fine line patterns ofyellow, magenta, cyan and black were printed. These fine line patternswere then visually evaluated according to the criterion (1). For theevaluation of running of black line, the magenta ink was solid-printedbefore the printing of fine black line. The print was then observed forrunning due to contact of the two colors according to the criterion (2).

5) For the evaluation of waterproofness, the image obtained was dippedin deionized water for 5 seconds. The image was then visually observedfor running.

6) For the evaluation of image preservability, a black-printed samplewas prepared. The sample thus prepared was then evaluated for thefollowing properties.

For the evaluation of light-fastness, the print which had just beenformed was measured for chromaticity (a*1, b*1) and brightness (L1)using SPM100-II (produced by Gretag Inc.), irradiated with light from axenon lamp (850,000 lux) using a weatherometer produced by Atlas Inc.for 7 days, and then again measured for chromaticity (a*1, b*1) andbrightness (L2). The color difference (ΔE) between before and afterirradiation was then determined and evaluated as follows:ΔE=((a*1−a*2)²+(b*1−b*2)²+(L1−L2)²)^(1/2)

The color difference was evaluated at three points of reflectiondensity, i.e., 1, 1.3 and 1.6. Those showing a color difference of notgreater than 5 at any of these reflection density points were ranked A.Those showing a color difference of not smaller than 5 at two of thesereflection density points were ranked B. Those showing a colordifference of not smaller than 5 at any of these reflection densitypoints were ranked C.

For the evaluation of heat fastness, the color difference between beforeand after storage at 80° C. for 6 days was determined in the same manneras in the evaluation of light-fastness. The percent dye remaining wasevaluated at three points of reflection density, i.e., 1, 1.3 and 1.6.Those showing a color difference of not greater than 3 at any of thesereflection density points were ranked A. Those showing a colordifference of not smaller than 3 at two of these reflection densitypoints were ranked B. Those showing a color difference of not smallerthan 5 at any of these reflection density points were ranked C.

For the evaluation of gas fastness, the color difference between beforeand after storage in ozone having a concentration of 0.5 ppm for 7 dayswas determined in the same manner as in the evaluation oflight-fastness. The percent dye remaining was evaluated at three pointsof reflection density, i.e., 1, 1.3 and 1.6. Those showing a colordifference of not greater than 10 at any of these reflection densitypoints were ranked A. Those showing a color difference of not smallerthan 10 at two of these reflection density points were ranked B. Thoseshowing a color difference of not smaller than 10 at any of thesereflection density points were ranked C. The results are set forth inTables C and D. TABLE C Printing Printing Running Running Water- Inkproperties properties Dry- of fine of fine proof- set (1) (2) abilityline (1) line (2) ness 101 A A G G G G (good) 102 A A G G G G 103 A A GG G G 104 A A G G G G 105 A A G G G G

TABLE D Ink set Light-fastness Heat fastness Gas fastness 101 B C C 102A A B 103 A A A 104 A A B 105 A A B

As can be seen in these results, the use of the ink composition of theinvention makes it possible to prevent the clogging of the nozzle andhence provide an excellent ejection stability as well as an excellentwaterproofness and fastness. It can be also seen that the inkcomposition of the invention doesn't run when printed in fine line toadvantage.

Even when the image-receiving paper to be used in the invention waschanged to a color photographic paper (photographic finish) for ink jetrecording produced by Fuji Photo Film Co., Ltd. or PR101 (produced byCanon Inc.), the same results as mentioned above were obtained. The sameeffects were obtained also when Surfynol 465 was replaced by or used incombination with a surface active agent as disclosed in Japanese PatentApplication No. 2001-80090, Japanese Patent Application No. 2001-11821or Japanese Patent Application No. 2001-11822.

Example 2

The same inks as prepared in Example 1 were each packed in a TypeBJ-F850 ink jet printer (produced by Canon Inc.) by which an image wasthen printed on a color ink jet paper (photographic finish) produced byFuji Photo Film Co., Ltd. These printed matters were each then evaluatedin the same tanner as in Example 1. As a result, the same results asobtained in Example 1 were obtained. The same effects were obtained alsowhen the image-receiving paper was changed to a PM photographic paperproduced by EPSON CO., LTD. or PR101 (produced by Canon Inc.).

Example 3

An ink set 201 was prepared in the same manner as in Example 1 exceptthat the yellow, light magenta, magenta, light cyan and cyan inks werechanged to oil-soluble dye-containing inks prepared in the followingmanner.

8 g of Dye (A-1) and 19.2 g of a surface active agent (Emal 20 C,produced by Kao Corp.) were dissolved in a mixture of 6 g of a highboiling organic solvent (S-1), 10 g of a high boiling organic solvent(S-2), 1.9 g of an additive (W-1) and 50 ml of ethyl acetate at 70° C.To this solution was then added 500 ml of deionized water with stirringby a magnetic stirrer to prepare a oil-in-water type coarse dispersion.

Subsequently, the coarse dispersion was passed through a microfluidizer(produced by MICROFLUIDEX INC.) at 60 MPa five times to undergo finedivision. The resulting emulsion was then subjected to desolvation usinga rotary evaporator until there occurred no odor of ethyl acetate.

To the fine emulsion of hydrophobic dye thus obtained were then added140 g of diethylene glycol, 64 g of glycerin and additives such as urea.To the emulsion was then added deionized water to make 11. The emulsionwas then adjusted to pH 9 with 10 mol/l KOH to prepare a light magentaink having a concentration set forth in Table E. The emulsion dispersionink thus obtained was then measured for volume-average particle sizeusing a Type UPA microtrack (produced by NIMSO CO., LTD.). The resultwas 40 nm.

An ink set 201 was prepared by changing the kind and amount of dyesused, the amount of high boiling solvents used and the kind and amountof various additives used as set forth in Table E. Table E indicates theformulation of the final composition obtained after the evaporation ofsolvent. TABLE E Light magenta Magenta Light cyan Cyan Yellow Black Dye(g/l) A-1 (5.00) A-1 (20.0) A-2 (11.2) A-2 (44.6)) A-3 (27.2) A-1 (10.0)A-2 (18.6) A-3 (13.6) High boiling S-1 (3.75) 14.52  8.1 32.4 19.7 30.6organic S-2 (6.25) 25.52 14.3 57.1 34.7 53.8 solvent (g/l) Additive W-1 0.625  2.5  1.2  4.8  3.4  5.2 (g/l) Emal 20 c (g/l) 12.0 40 15.5 62 5072.4 Diethylene 87.5 87.5 87.5 87.5 87.5 87.5 glycol (g/l) Glycerin 40.040.0 40.0 46.0 46.0 46.0 (g/l) Surfynol 465 10.0 10.0 10.0 10.0 10.010.0 (g/l) Triethanol-  7.5  7.5  7.5  7.5  7.5  7.5 amine (g/l) Benzo- 0.075  0.075  0.075  0.075  0.075  0.075 triazole (g/l) Proxel XL2  2.5 2.5  2.5  2.5  2.5  2.5 (g/l) Deionized water to make 1 litterVolume-average 40 nm 43 31 41 45 60 particle size S-1

S-2

W-1

A-1

A-2

A-3

Ink sets 202 to 205 were prepared in the same manner as in the ink set201 except that the kind of dyes to be incorporated in the various inkswere changed as set forth in Table F. In the case where the dyes werechanged, they were used in equimolecular amounts and their concentrationwas adjusted such that the transmission density of the various inksolutions was the same as in the ink set 201. In the case where aplurality of dyes were used in combination, they were used inequimolecular amounts. TABLE F Light Light Ink set cyan Cyan magentaMagenta Yellow Remarks 201 A-2 A-2 A-1 A-1 A-3 Comparative 202 (103)(103) a-24 a-24 YI-57 Inventive 203 (103) (109) a-24 a-24  YI-104Inventive 204 144 137 b-3  d-3   YI-105 Inventive 142 c-5  e-1  YI-56205 A-2 A-2 A-1 A-1 A-3 Inventive (103) (103) (a-24) a-24 YI-57

Subsequently, the ink sets 201 to 208 were each packed in the cartridgeof a Type PM670C ink jet printer (produced by EPSON Co., LTD.) by whichan image was then printed on a color ink jet paper (photographic finish)produced by Fuji Photo Film Co., Ltd. Then, the following propertieswere evaluated.

1) For the evaluation of printing properties (1), the cartridge wasmounted on the printer. The ejection of ink through all the nozzles wasthen confirmed. An image was then printed on 30 sheets of A4 size paper.The printer matter was then evaluated for disturbance in print.

A. No disturbance in print between the beginning and the end ofprinting;

B: Some disturbance in print

C: Disturbance in print between the beginning and the end of printing

2) For the evaluation of printing properties (2), the cartridge wasallowed to stand at 60° C. for 2 days. The printed matter was thenevaluated for disturbance in print in the same manner as in the printingproperties (1).

3) For the evaluation of dryability, the images which had just beenformed were touched with a finger. The finger was then visually observedfor stain.

4) For the evaluation of running of fine line, fine line patterns ofyellow, magenta, cyan and black were printed. These fine line patternswere then visually evaluated according to the criterion (1). For theevaluation of running of black line, the magenta ink was solid-printedbefore the printing of fine black line. The print was then observed forrunning due to contact of the two colors according to the criterion (2).

5) For the evaluation of waterproofness, the image obtained was dippedin deionized water for 5 seconds. The image was then visually observedfor running.

6) For the evaluation of image preservability, a black-printed samplewas prepared. The sample thus prepared was then evaluated for thefollowing properties.

For the evaluation of light-fastness, the print which had just beenformed was measured for chromaticity (a*1, b*1) and brightness (L1)using a chromaticity meter produced by Gretag Inc., irradiated withlight from a xenon lamp (850,000 lux) using a weatherometer produced byAtlas Inc. for 10 days, and then again measured for chromaticity (a*1,b*1) and brightness (L2). The color difference (NE) between before andafter irradiation was then determined and evaluated as follows:ΔE={(a*1−a*2)²+(b*1−b*2)²+(L1−L2)²}^(1/2)

The color difference was evaluated at three points of reflectiondensity, i.e., 1, 1.3 and 1.6. Those showing a color difference of notgreater than 5 at any of these reflection density points were ranked A.Those showing a color difference of not smaller than 5 at two of thesereflection density points were ranked S. Those showing a colordifference of not smaller than 5 at any of these reflection densitypoints were ranked C.

For the evaluation of heat fastness, the color difference between beforeand after storage at 80° C. for 4 days was determined in the same manneras in the evaluation of light-fastness. The percent dye remaining wasevaluated at three points of reflection density, i.e., 1, 1.3 and 1.6.Those showing a color difference of not greater than 5 at any of thesereflection density points were ranked A. Those showing a colordifference of not smaller than 5 at two of these reflection densitypoints were ranked B. Those showing a color difference of not smallerthan 5 at any of these reflection density points were ranked C.

For the evaluation of gas fastness, the color difference between beforeand after storage in ozone having a concentration of 1.0 ppm for 2 dayswas determined in the same manner as in the evaluation oflight-fastness. The percent dye remaining was evaluated at three pointsof reflection density, i.e., 1, 1.3 and 1.6. Those showing a colordifference of not greater than 10 at any of these reflection densitypoints were ranked A. Those showing a color difference of not smallerthan 10 at two of these reflection density points were ranked B. Thoseshowing a color difference of not smaller than 10 at any of thesereflection density points were ranked C. The results are set forth inTables G and H. TABLE G Printing Printing Running Running Water- Inkproperties properties Dry- of fine of fine proof- set (1) (2) abilityline (1) line (2) ness 201 A A G G G G (good) 202 A A G G G G 203 A A GG G G 204 A A G G G G 205 A A G G G G

TABLE H Ink set Light-fastness Heat fastness Gas fastness 201 B C C 202A A B 203 A A A 204 A A B 205 B B B

As can be seen in these results, the use of the ink composition of theinvention makes it possible to prevent the clogging of the nozzle andhence provide an excellent ejection stability as well as an excellentwaterproofness. Referring to fastness, the ink composition of theinvention shows little chromaticity change at black area. It can be alsoseen that the ink composition of the invention doesn't run when printedin fine line to advantage.

Even when the image-receiving paper to be used in the invention waschanged to a PM photographic paper produced by EPSON CO., LTD. or PR101(produced by Canon Inc.), the same results as mentioned above wereobtained.

As can be seen in these results, the use of the ink composition of theinvention makes it possible to prevent the clogging of the nozzle andhence provide an excellent ejection stability as well as an excellentwaterproofness and fastness. It can be also seen that the inkcomposition of the invention doesn't run when printed in fine line toadvantage, Even when the image-receiving paper to be used in theinvention was changed to a PM photographic paper produced by EPSON CO.,LTD. or PR101 (produced by Canon Inc.), the same results as mentionedabove were obtained. The same effects were obtained also when Surfynol465 was replaced by or used in combination with a surface active agentas disclosed in Japanese Patent Application No. 2001-80090, JapanesePatent Application No. 2001-11821 or Japanese Patent Application No.2001-11822.

Example 4

The same inks as prepared in Example 1 were each packed in a TypeBJ-F850 ink jet printer (produced by Canon Inc.) by which an image wasthen printed on a color ink jet paper (photographic finish) produced byFuji Photo Film Co., Ltd. These printed matters were each then evaluatedin the same manner as in Example 3. As a result, the same results asobtained in Example 1 were obtained. The same effects were obtained alsowhen the image-receiving paper was changed to a PM photographic paperproduced by EPSON CO., LTD. or PR101 (produced by Canon Inc.).

The use of the ink set of the invention makes it possible to provideexcellence in handleability, odor, safety, etc., and a high ejectionstability and give an image having an excellent hue, light-resistanceand waterproofness free of defectives of image quality such as runningof fine line and improve the image preservability under severeconditions. Accordingly, the ink set and ink cartridge of the inventionand the printer having them mounted therein can maintain an excellentejection stability over an extended period of time even after aged undersevere conditions. The resulting printed matters, too, exhibit a highfastness.

The entire disclosure of each and every foreign patent application:Japanese Patent Applications No. 2002-242238, from which the benefit offoreign priority has been claimed in the present application isincorporated herein by reference, as if fully set forth.

1-12. (canceled)
 13. An ink set comprising a plurality of inks differentin hues, wherein the plurality of inks includes a yellow ink containinga coloring agent that is a dye represented by the following generalformula (2-1), the dye having a λmax of from 390 nm to 470 nm:

wherein R²¹ and R²³ each represent a hydrogen atom, alkyl group,cycloalkyl group, alkoxy group or aryl group; R²² represents an arylgroup or heterocyclic group; and one of X and Y represents a nitrogenatom and the other represents —CR²⁴ in which R²⁴ represents a hydrogenor halogen atom or a cyano, alkyl, alkylthio, alkylsulfonyl,alkylsulfinyl, alkyloxycarbonyl, carbamoyl, alkoxy, aryl, arylthio,arylsulfonyl, arylsulfinyl, aryloxy or acylamino group which may befurther substituted.
 14. The ink set as in claim 13, which furthercomprises at least a coloring agent represented by the following generalformula (M-I) as the magenta ink:

wherein A¹ represents a residue of a 5-membered heterocyclic diazocomponent A¹-NH₂; B¹ and B² each represent a nitrogen atom, —CR¹═ or—CR²═, and when one of B¹ and B² represents a nitrogen atom, the otherrepresents —CR¹═ or —CR²═; R⁵ and R⁶ each independently represents ahydrogen atom, an aliphatic group, an aromatic group, a heterocyclicgroup, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group,a carbamoyl group, an alkyl- or arylsulfonyl group or a sulfamoyl group,which may further have a substituent group; G1, R1 and R2 eachindependently represents a hydrogen atom, a halogen atom, an aliphaticgroup, an aromatic group, a heterocyclic group, a cyano group, acarboxyl group, a carbamoyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a heterocyclic oxycarbonyl group, an acyl group,a hydroxyl group, an alkoxyl group, an aryloxy group, a heterocyclic oxygroup, a silyloxy group, an acyloxy group, a carbamoyloxy group, analkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group(containing a heterocyclic amino group and an aniline group), anacylamino group, a ureido group, a sulfamoylamino group, analkoxycarbonylamino group, an aryloxycarbonylamino group, an alkyl- orarylsulfonylamino group, a heterocyclic sulfonylamino group, a nitrogroup, an alkyl- or arylthio group, an alkyl- or arylsulfonyl group, aheterocyclic sulfonyl group, an alkyl- or arylsulfinyl group, aheterocyclic sulfinyl group, a sulfamoyl group, a sulfo group or aheterocyclic thio group, which may be further substituted; and R¹ andR⁵, or R⁵ and R⁶ may combine with each other to form a 5- or 6-memberedring.
 15. The ink set as in claim 13, which further comprises a coloringagent represented by the following general formula (C-I) as the cyanink:

wherein X¹, X², X³ and X⁴ each independently represent —SO-Z¹, —SO₂Z¹,—SO₂NRZ¹R²², —CONR²¹R²² or —CO₂R²¹ in which Z¹ represents a substitutedor unsubstituted alkyl, cycloalkyl, alkenyl, aralkyl, aryl orheterocyclic group; and R²¹ and R²² each independently represent ahydrogen atom or a substituted or unsubstituted alkyl, cycloalkyl,alkenyl, aralkyl, aryl or heterocyclic group; Y¹, Y², Y³ and Y⁴ eachindependently represent a monovalent substituent; a1 to a4 and b 1 to b4each independently represent an integer of from 0 to 4 indicating thenumber of substituents X¹ to X⁴ and Y¹ to Y⁴, with the proviso that a1to a4 are not 0 at the same time and when a1 to a4 and b1 to b4 eachrepresent an integer of not smaller than 2, the plurality of X¹'s toX⁴'s and Y¹'s to Y⁴'s may be the same or different; and M represents ahydrogen atom or a metal, atom, or oxide, hydroxide or halide thereof.16. The ink set as in claim 14, wherein the magenta ink includes a setof two or more inks different in ink concentration, and the inkconcentration of one magenta ink is 0.05 to 0.5 time that of the othermagenta ink.
 17. The ink set as in claim 15, wherein the cyan inkincludes a set of two or more inks different in ink concentration, andthe ink concentration of one cyan ink is 0.05 to 0.5 time that of theother magenta ink.
 18. A color ink cartridge comprising at least ayellow ink, wherein the yellow ink includes the coloring agent as inclaim
 13. 19. The ink cartridge as in claim 18, which further comprises:a coloring agent represented by the following general formula (M-I) asthe magenta ink; and a coloring agent represented by the followinggeneral formula (C-I) as the cyan ink:

wherein A¹ represents a residue of a 5-membered heterocyclic diazocomponent A¹-NH²; B¹ and B² each represent a nitrogen atom, —CR¹═ or—CR²═, and when one of B¹ and B² represents a nitrogen atom, the otherrepresents —CR¹═ or —CR²═; R⁵ and R⁶ each independently represents ahydrogen atom, an aliphatic group, an aromatic group, a heterocyclicgroup, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group,a carbamoyl group, an alkyl- or arylsulfonyl group or a sulfamoyl group,which may further have a substituent group; G¹, R¹ and R² eachindependently represents a hydrogen atom, a halogen atom, an aliphaticgroup, an aromatic group, a heterocyclic group, a cyano group, acarboxyl group, a carbamoyl group, an alkoxycarbonyl group, anaryloxycarbonyl group, a heterocyclic oxycarbonyl group, an acyl group,a hydroxyl group, an alkoxyl group, an aryloxy group, a heterocyclic oxygroup, a silyloxy group, an acyloxy group, a carbamoyloxy group, analkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group(containing a heterocyclic amino group and an anilino group), anacylamino group, a ureido group, a sulfamoylamino group, analkoxycarbonylamino group, an aryloxycarbonylamino group, an alkyl- orarylsulfonylamino group, a heterocyclic sulfonylamino group, a nitrogroup, an alkyl- or arylthio group, an alkyl- or arylsulfonyl group, aheterocyclic sulfonyl group, an alkyl- or arylsulfinyl group, aheterocyclic sulfinyl group, a sulfamoyl group, a sulfo group or aheterocyclic thio group, which may be further substituted; and R1 andR⁵, or R⁵ and R⁶ may combine with each other to form a 5- or 6-memberedring,

wherein X¹, X², X³ and X⁴ each independently represent —SO-Z¹, —SO₂Z¹,—SO₂NR²¹R²², —CONR²¹R²² or —CO₂R²¹ in which Z¹ represents a substitutedor unsubstituted alkyl, cycloalkyl, alkenyl, aralkyl, aryl orheterocyclic group; and R²¹ and R²² each independently represent ahydrogen atom or a substituted or unsubstituted alkyl, cycloalkyl,alkenyl, aralkyl, aryl or heterocyclic group; Y¹, Y², Y³ and Y⁴ eachindependently represent a monovalent substituent; a1 to a4 and b1 to b4each independently represent an integer of from 0 to 4 indicating thenumber of substituents X¹ to X⁴ and Y¹ to Y⁴, with the proviso that a1to a4 are not 0 at the same time and when a1 to a4 and b1 to b4 eachrepresent an integer of not smaller than 2, the plurality of X¹'s toX⁴'s and Y¹'s to Y⁴'s may be the same or different; and M represents ahydrogen atom or a metal atom, or oxide, hydroxide or halide thereof.20. An ink jet printer using the ink set as in claim
 13. 21. An imagerecording method which comprises using the ink set as in claim 13 toconduct color printing.
 22. An ink set as in claim 13, wherein R²² is atriazine ring.